diff --git a/configure.ac b/configure.ac
index 49e37e2..45c7f3d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -179,6 +179,8 @@ AX_CHECK_COMPILE_FLAG([-Werror=implicit-function-declaration], [CFLAGS="$CFLAGS
 AX_CHECK_COMPILE_FLAG([-Wmissing-declarations], [CFLAGS="$CFLAGS -Wmissing-declarations"], [], [-Werror])
 AX_CHECK_COMPILE_FLAG([-Wunused-function], [CFLAGS="$CFLAGS -Wunused-function"], [], [-Werror])
 AX_CHECK_COMPILE_FLAG([-Wunused-variable], [CFLAGS="$CFLAGS -Wunused-variable"], [], [-Werror])
+# Useful to catch non-standard constructs.
+AX_CHECK_COMPILE_FLAG([-Wpedantic], [CFLAGS="$CFLAGS -Wpedantic"], [], [-Werror])
 
 dnl Treat warnings as errors
 AC_ARG_ENABLE([werror],
diff --git a/src/encoder/formats.c_template b/src/encoder/formats.c_template
index 8ffdc79..6e7700f 100644
--- a/src/encoder/formats.c_template
+++ b/src/encoder/formats.c_template
@@ -22,7 +22,7 @@
 #include "encoder/encoder.h"
 #include "encoder/EMInst.h"
 
-static char *formatName[];
+static char *formatName[NUM_FORMATS+1];
 
 char *instFormatName(InstID instID)
 {