diff --git a/cmake/FindAmplifier.cmake b/cmake/FindAmplifier.cmake
index 41ffbf74434e..7b5e450726fb 100644
--- a/cmake/FindAmplifier.cmake
+++ b/cmake/FindAmplifier.cmake
@@ -37,7 +37,7 @@ if(NOT TARGET Amplifier::amplifier)
   if(Amplifier_ROOT)
     # The call to file is for compatibility for windows paths
     file(TO_CMAKE_PATH ${Amplifier_ROOT} Amplifier_ROOT)
-  elseif("$ENV{AMPLIFIER_ROOT}")
+  elseif(DEFINED ENV{AMPLIFIER_ROOT})
     file(TO_CMAKE_PATH $ENV{AMPLIFIER_ROOT} Amplifier_ROOT)
   else()
     file(TO_CMAKE_PATH "${Amplifier_INCLUDE_DIR}" Amplifier_INCLUDE_DIR)
diff --git a/cmake/FindAsio.cmake b/cmake/FindAsio.cmake
index 76fea2033ddd..8141b020cb88 100644
--- a/cmake/FindAsio.cmake
+++ b/cmake/FindAsio.cmake
@@ -33,7 +33,7 @@ if(NOT TARGET Asio::asio)
   if(Asio_ROOT)
     # The call to file is for compatibility with windows paths
     file(TO_CMAKE_PATH ${Asio_ROOT} Asio_ROOT)
-  elseif("$ENV{ASIO_ROOT}")
+  elseif(DEFINED ENV{ASIO_ROOT})
     file(TO_CMAKE_PATH $ENV{ASIO_ROOT} Asio_ROOT)
   else()
     file(TO_CMAKE_PATH "${Asio_INCLUDE_DIR}" Asio_INCLUDE_DIR)
diff --git a/cmake/FindHwloc.cmake b/cmake/FindHwloc.cmake
index 42d331e65f70..a69971059741 100644
--- a/cmake/FindHwloc.cmake
+++ b/cmake/FindHwloc.cmake
@@ -51,7 +51,7 @@ if(NOT TARGET Hwloc::hwloc)
   if(Hwloc_ROOT)
     # The call to file is for compatibility with windows paths
     file(TO_CMAKE_PATH ${Hwloc_ROOT} Hwloc_ROOT)
-  elseif("$ENV{HWLOC_ROOT}")
+  elseif(DEFINED ENV{HWLOC_ROOT})
     file(TO_CMAKE_PATH $ENV{HWLOC_ROOT} Hwloc_ROOT)
   else()
     file(TO_CMAKE_PATH "${Hwloc_INCLUDE_DIR}" Hwloc_INCLUDE_DIR)
diff --git a/cmake/FindJemalloc.cmake b/cmake/FindJemalloc.cmake
index c6e111ede3a2..c5778013a08f 100644
--- a/cmake/FindJemalloc.cmake
+++ b/cmake/FindJemalloc.cmake
@@ -53,7 +53,7 @@ endif()
 if(Jemalloc_ROOT)
   # The call to file is for compatibility with windows paths
   file(TO_CMAKE_PATH ${Jemalloc_ROOT} Jemalloc_ROOT)
-elseif("$ENV{JEMALLOC_ROOT}")
+elseif(DEFINED ENV{JEMALLOC_ROOT})
   file(TO_CMAKE_PATH $ENV{JEMALLOC_ROOT} Jemalloc_ROOT)
 else()
   file(TO_CMAKE_PATH "${Jemalloc_INCLUDE_DIR}" Jemalloc_INCLUDE_DIR)
@@ -75,7 +75,7 @@ find_library(
 )
 
 # Set Jemalloc_ROOT in case the other hints are used
-if(NOT Jemalloc_ROOT AND "$ENV{JEMALLOC_ROOT}")
+if(NOT Jemalloc_ROOT AND DEFINED ENV{JEMALLOC_ROOT})
   set(Jemalloc_ROOT $ENV{JEMALLOC_ROOT})
 elseif(NOT Jemalloc_ROOT)
   string(REPLACE "/include" "" Jemalloc_ROOT "${Jemalloc_INCLUDE_DIR}")
diff --git a/cmake/FindLibSigSegv.cmake b/cmake/FindLibSigSegv.cmake
index e37bac02a0b6..979f461a00f7 100644
--- a/cmake/FindLibSigSegv.cmake
+++ b/cmake/FindLibSigSegv.cmake
@@ -45,7 +45,7 @@ find_library(
 if(Libsigsegv_ROOT)
   # The call to file is for compatibility with windows paths
   file(TO_CMAKE_PATH ${Libsigsegv_ROOT} Libsigsegv_ROOT)
-elseif("$ENV{LIBSIGSEGV_ROOT}")
+elseif(DEFINED ENV{LIBSIGSEGV_ROOT})
   file(TO_CMAKE_PATH $ENV{LIBSIGSEGV_ROOT} Libsigsegv_ROOT)
 else()
   file(TO_CMAKE_PATH "${Libsigsegv_INCLUDE_DIR}" Libsigsegv_INCLUDE_DIR)
diff --git a/cmake/FindLibfabric.cmake b/cmake/FindLibfabric.cmake
index ce6a3a247835..a0e969c64365 100644
--- a/cmake/FindLibfabric.cmake
+++ b/cmake/FindLibfabric.cmake
@@ -33,7 +33,7 @@ find_library(
 if(Libfabric_ROOT)
   # The call to file is for compatibility with windows paths
   file(TO_CMAKE_PATH ${Libfabric_ROOT} Libfabric_ROOT)
-elseif("$ENV{LIBFABRIC_ROOT}")
+elseif(DEFINED ENV{LIBFABRIC_ROOT})
   file(TO_CMAKE_PATH $ENV{LIBFABRIC_ROOT} Libfabric_ROOT)
 else()
   file(TO_CMAKE_PATH "${Libfabric_INCLUDE_DIR}" Libfabric_INCLUDE_DIR)
diff --git a/cmake/FindMSR.cmake b/cmake/FindMSR.cmake
index fb7c2a41526c..7e16aae1138a 100644
--- a/cmake/FindMSR.cmake
+++ b/cmake/FindMSR.cmake
@@ -37,7 +37,7 @@ find_library(
 if(Msr_ROOT)
   # The call to file is for compatibility with windows paths
   file(TO_CMAKE_PATH ${Msr_ROOT} Msr_ROOT)
-elseif("$ENV{MSR_ROOT}")
+elseif(DEFINED ENV{MSR_ROOT})
   file(TO_CMAKE_PATH $ENV{MSR_ROOT} Msr_ROOT)
 else()
   file(TO_CMAKE_PATH "${Msr_INCLUDE_DIR}" Msr_INCLUDE_DIR)
diff --git a/cmake/FindOrangeFS.cmake b/cmake/FindOrangeFS.cmake
index 36caaaaa0f26..ac5ab29d8b69 100644
--- a/cmake/FindOrangeFS.cmake
+++ b/cmake/FindOrangeFS.cmake
@@ -37,7 +37,7 @@ find_library(
 if(Orangefs_ROOT)
   # The call to file is for compatibility with windows paths
   file(TO_CMAKE_PATH ${Orangefs_ROOT} Orangefs_ROOT)
-elseif("$ENV{ORANGEFS_ROOT}")
+elseif(DEFINED ENV{ORANGEFS_ROOT})
   file(TO_CMAKE_PATH $ENV{ORANGEFS_ROOT} Orangefs_ROOT)
 else()
   file(TO_CMAKE_PATH "${Orangefs_INCLUDE_DIR}" Orangefs_INCLUDE_DIR)
diff --git a/cmake/FindPWR.cmake b/cmake/FindPWR.cmake
index 0007fa6008dc..6e6e1eeca357 100644
--- a/cmake/FindPWR.cmake
+++ b/cmake/FindPWR.cmake
@@ -54,7 +54,7 @@ if(NOT TARGET PWR::pwr)
   if(Pwr_ROOT)
     # The call to file is for compatibility with windows paths
     file(TO_CMAKE_PATH ${Pwr_ROOT} Pwr_ROOT)
-  elseif("$ENV{PWR_ROOT}")
+  elseif(DEFINED ENV{PWR_ROOT})
     file(TO_CMAKE_PATH $ENV{PWR_ROOT} Pwr_ROOT)
   else()
     file(TO_CMAKE_PATH "${Pwr_INCLUDE_DIR}" Pwr_INCLUDE_DIR)
diff --git a/cmake/FindPapi.cmake b/cmake/FindPapi.cmake
index b0a4dbf4cf2e..5f0592f5a258 100644
--- a/cmake/FindPapi.cmake
+++ b/cmake/FindPapi.cmake
@@ -36,7 +36,7 @@ if(NOT TARGET Papi::papi)
   )
 
   # Set Papi_ROOT in case the other hints are used
-  if(NOT Papi_ROOT AND "$ENV{PAPI_ROOT}")
+  if(NOT Papi_ROOT AND DEFINED ENV{PAPI_ROOT})
     set(Papi_ROOT $ENV{PAPI_ROOT})
   elseif(NOT Papi_ROOT)
     string(REPLACE "/include" "" Papi_ROOT "${Papi_INCLUDE_DIR}")
@@ -46,7 +46,7 @@ if(NOT TARGET Papi::papi)
   if(Papi_ROOT)
     # The call to file is for compatibility with windows paths
     file(TO_CMAKE_PATH ${Papi_ROOT} Papi_ROOT)
-  elseif("$ENV{PAPI_ROOT}")
+  elseif(DEFINED ENV{PAPI_ROOT})
     file(TO_CMAKE_PATH $ENV{PAPI_ROOT} Papi_ROOT)
   else()
     file(TO_CMAKE_PATH "${Papi_INCLUDE_DIR}" Papi_INCLUDE_DIR)
diff --git a/cmake/FindQThreads.cmake b/cmake/FindQThreads.cmake
index 08e2342521fb..1e555ce48aa1 100644
--- a/cmake/FindQThreads.cmake
+++ b/cmake/FindQThreads.cmake
@@ -36,7 +36,7 @@ find_library(
 if(Qthreads_ROOT)
   # The call to file is for compatibility with windows paths
   file(TO_CMAKE_PATH ${Qthreads_ROOT} Qthreads_ROOT)
-elseif("$ENV{QTHREADS_ROOT}")
+elseif(DEFINED ENV{QTHREADS_ROOT})
   file(TO_CMAKE_PATH $ENV{QTHREADS_ROOT} Qthreads_ROOT)
 else()
   file(TO_CMAKE_PATH "${Qthreads_INCLUDE_DIR}" Qthreads_INCLUDE_DIR)
diff --git a/cmake/FindTBBmalloc.cmake b/cmake/FindTBBmalloc.cmake
index 9b029ac51068..fa796dbb717f 100644
--- a/cmake/FindTBBmalloc.cmake
+++ b/cmake/FindTBBmalloc.cmake
@@ -53,7 +53,7 @@ find_library(
 )
 
 # Set Tbbmalloc_ROOT in case the other hints are used
-if(NOT Tbbmalloc_ROOT AND "$ENV{TBBMALLOC_ROOT}")
+if(NOT Tbbmalloc_ROOT AND DEFINED ENV{TBBMALLOC_ROOT})
   set(Tbbmalloc_ROOT $ENV{TBBMALLOC_ROOT})
 elseif(NOT Tbbmalloc_ROOT)
   string(REPLACE "/include" "" Tbbmalloc_ROOT "${Tbbmalloc_INCLUDE_DIR}")
diff --git a/cmake/FindTCMalloc.cmake b/cmake/FindTCMalloc.cmake
index 8503410b8d94..55bd5e3d0c25 100644
--- a/cmake/FindTCMalloc.cmake
+++ b/cmake/FindTCMalloc.cmake
@@ -48,7 +48,7 @@ find_library(
 )
 
 # Set Tcmalloc_ROOT in case the other hints are used
-if(NOT Tcmalloc_ROOT AND "$ENV{TCMALLOC_ROOT}")
+if(NOT Tcmalloc_ROOT AND DEFINED ENV{TCMALLOC_ROOT})
   set(Tcmalloc_ROOT $ENV{TCMALLOC_ROOT})
 elseif(NOT Tcmalloc_ROOT)
   string(REPLACE "/include" "" Tcmalloc_ROOT "${Tcmalloc_INCLUDE_DIR}")
diff --git a/cmake/HPX_SetupApex.cmake b/cmake/HPX_SetupApex.cmake
index 2b3d071e50c5..9723a7d1c8ac 100644
--- a/cmake/HPX_SetupApex.cmake
+++ b/cmake/HPX_SetupApex.cmake
@@ -39,7 +39,7 @@ if(HPX_WITH_APEX AND NOT TARGET APEX::apex)
   endif()
 
   if(NOT HPX_FIND_PACKAGE)
-    if(NOT "${Apex_ROOT}" AND "$ENV{APEX_ROOT}")
+    if(NOT "${Apex_ROOT}" AND DEFINED ENV{APEX_ROOT})
       set(Apex_ROOT "$ENV{APEX_ROOT}")
     endif()
 
diff --git a/cmake/HPX_SetupBoost.cmake b/cmake/HPX_SetupBoost.cmake
index 14aa36c25df8..43360e5571db 100644
--- a/cmake/HPX_SetupBoost.cmake
+++ b/cmake/HPX_SetupBoost.cmake
@@ -153,7 +153,7 @@ if(NOT TARGET hpx_dependencies_boost)
   endif()
 
   # We are assuming that there is only one Boost Root
-  if(NOT Boost_ROOT AND "$ENV{BOOST_ROOT}")
+  if(NOT Boost_ROOT AND DEFINED ENV{BOOST_ROOT})
     set(Boost_ROOT $ENV{BOOST_ROOT})
   elseif(NOT Boost_ROOT)
     string(REPLACE "/include" "" Boost_ROOT "${Boost_INCLUDE_DIRS}")
diff --git a/cmake/HPX_SetupGasnet.cmake b/cmake/HPX_SetupGasnet.cmake
index 61690c08ddae..a63cbc7980a0 100644
--- a/cmake/HPX_SetupGasnet.cmake
+++ b/cmake/HPX_SetupGasnet.cmake
@@ -171,7 +171,7 @@ macro(hpx_setup_gasnet)
         elseif(${MPI_CC})
           set(MPI_CC ${CMAKE_C_COMPILER})
           set(ENV{MPI_CC} ${CMAKE_C_COMPILER})
-        elseif($ENV{MPI_CC})
+        elseif(DEFINED ENV{MPI_CC})
           set(MPI_CC ${CMAKE_C_COMPILER})
           set(ENV{MPI_CC} ${CMAKE_C_COMPILER})
         else()
diff --git a/cmake/templates/HPXConfig.cmake.in b/cmake/templates/HPXConfig.cmake.in
index 3c5161690bde..59f4d2cad8b5 100644
--- a/cmake/templates/HPXConfig.cmake.in
+++ b/cmake/templates/HPXConfig.cmake.in
@@ -149,7 +149,7 @@ set(HPX_TBBMALLOC_ROOT "@Tbbmalloc_ROOT@")
 # Special handle for mimalloc cause we can't specify HPX_MIMALLOC_ROOT as a HINT
 # to find_package
 set(HPX_MIMALLOC_ROOT "@Mimalloc_ROOT@")
-if(NOT Mimalloc_ROOT AND NOT "$ENV{MIMALLOC_ROOT}")
+if(NOT Mimalloc_ROOT AND NOT DEFINED ENV{MIMALLOC_ROOT})
   set(Mimalloc_ROOT ${HPX_MIMALLOC_ROOT})
 endif()
 include(HPX_SetupAllocator)
@@ -160,7 +160,7 @@ include(HPX_SetupThreads)
 set(HPX_BOOST_ROOT "@Boost_ROOT@")
 # By default Boost_ROOT is set to HPX_BOOST_ROOT (not necessary for PAPI or
 # HWLOC cause we are specifying HPX_<lib>_ROOT as an HINT to find_package)
-if(NOT Boost_ROOT AND NOT "$ENV{BOOST_ROOT}")
+if(NOT Boost_ROOT AND NOT DEFINED ENV{BOOST_ROOT})
   set(Boost_ROOT ${HPX_BOOST_ROOT})
 endif()
 include(HPX_SetupBoost)
diff --git a/libs/full/parcelport_libfabric/cmake/FindPMI.cmake b/libs/full/parcelport_libfabric/cmake/FindPMI.cmake
index ef7073ab1262..3e3a45da1a15 100644
--- a/libs/full/parcelport_libfabric/cmake/FindPMI.cmake
+++ b/libs/full/parcelport_libfabric/cmake/FindPMI.cmake
@@ -55,7 +55,7 @@ find_library(
 if(Pmi_ROOT)
   # The call to file is for compatibility with windows paths
   file(TO_CMAKE_PATH ${Pmi_ROOT} Pmi_ROOT)
-elseif("$ENV{PMI_ROOT}")
+elseif(DEFINED ENV{PMI_ROOT})
   file(TO_CMAKE_PATH $ENV{PMI_ROOT} Pmi_ROOT)
 else()
   file(TO_CMAKE_PATH "${Pmi_INCLUDE_DIR}" Pmi_INCLUDE_DIR)