diff --git a/tests/headers/UCD-E2V-CCD250-TS_C_20230730_000237_R22_S01.yaml b/tests/headers/UCD-E2V-CCD250-TS_C_20230730_000237_R22_S01.yaml
index 9dc52b57a..9fa6413f4 100644
--- a/tests/headers/UCD-E2V-CCD250-TS_C_20230730_000237_R22_S01.yaml
+++ b/tests/headers/UCD-E2V-CCD250-TS_C_20230730_000237_R22_S01.yaml
@@ -1,12 +1,12 @@
-SIMPLE: True
-EXTEND: True
+SIMPLE: true
+EXTEND: true
 DATE: 2023-10-31T19:21:15.290
 MJD: 60248.806426967494
 CCD_MANU: E2V
 CCD_TYPE: CCD250
 TESTTYPE: FLAT
 IMGTYPE: FLAT
-DETSIZE: [1:4096,1:4004]
+DETSIZE: '[1:4096,1:4004]'
 EXPTIME: 1.0
 BINX: 1
 BINY: 1
@@ -25,7 +25,7 @@ CONTNUM: 18eda94e
 DAQVERS: davis-V4.15 2023-07-12T00:30:21Z (4b972d1)
 DAQPART: davis
 DAQFOLD: raw
-DAQANNOT: 
+DAQANNOT: ''
 OBSID: TS_C_20231031_000227
 TELCODE: TS
 CONTRLLR: C
@@ -113,7 +113,7 @@ AP0_AF1: 0
 AP1_AF1: 0
 AP0_TM: 0
 AP1_TM: 0
-HVBIAS: ON
+HVBIAS: 'ON'
 DATASUM: 0
-HIERARCH ASTRO METADATA FIX MODIFIED: False
+HIERARCH ASTRO METADATA FIX MODIFIED: false
 HIERARCH ASTRO METADATA FIX DATE: 2023-12-13T18:19:55.318445
diff --git a/tests/headers/UCD-ITL-3800C-TS_C_20231031_000227_R21_S01.yaml b/tests/headers/UCD-ITL-3800C-TS_C_20231031_000227_R21_S01.yaml
index 48ec8e108..fdd2e4d90 100644
--- a/tests/headers/UCD-ITL-3800C-TS_C_20231031_000227_R21_S01.yaml
+++ b/tests/headers/UCD-ITL-3800C-TS_C_20231031_000227_R21_S01.yaml
@@ -1,5 +1,5 @@
-SIMPLE: True
-EXTEND: True
+SIMPLE: true
+EXTEND: true
 HISTORY: = 'Amp Order Fixed'    / File modification log.
 DATE: 2023-07-30T22:24:06.591
 MJD: 60155.933409618214
@@ -7,7 +7,7 @@ CCD_MANU: ITL
 CCD_TYPE: 3800C
 TESTTYPE: FLAT
 IMGTYPE: FLAT
-DETSIZE: [1:4072,1:4000]
+DETSIZE: '[1:4072,1:4000]'
 EXPTIME: 2.0
 BINX: 1
 BINY: 1
@@ -26,7 +26,7 @@ CONTNUM: 18eda94e
 DAQVERS: davis-V4.15 2023-07-12T00:30:21Z (4b972d1)
 DAQPART: davis
 DAQFOLD: raw
-DAQANNOT: 
+DAQANNOT: ''
 OBSID: TS_C_20230730_000237
 TELCODE: TS
 CONTRLLR: C
@@ -114,7 +114,7 @@ AP0_AF1: 0
 AP1_AF1: 0
 AP0_TM: 0
 AP1_TM: 0
-HVBIAS: ON
+HVBIAS: 'ON'
 DATASUM: 0
-HIERARCH ASTRO METADATA FIX MODIFIED: False
+HIERARCH ASTRO METADATA FIX MODIFIED: false
 HIERARCH ASTRO METADATA FIX DATE: 2023-12-13T18:18:24.454546