diff --git a/bin/prms_win_gfort_dbl_prec.exe b/bin/prms_win_gfort_dbl_prec.exe
new file mode 100644
index 00000000..9ac58623
Binary files /dev/null and b/bin/prms_win_gfort_dbl_prec.exe differ
diff --git a/bin/prms_win_ifort_mixed_prec.exe b/bin/prms_win_ifort_mixed_prec.exe
deleted file mode 100755
index dfd2476e..00000000
Binary files a/bin/prms_win_ifort_mixed_prec.exe and /dev/null differ
diff --git a/prms_src/prms5.2.1/makelist_double_precision b/prms_src/prms5.2.1/makelist_double_precision
index 3f7df437..223f23cc 100644
--- a/prms_src/prms5.2.1/makelist_double_precision
+++ b/prms_src/prms5.2.1/makelist_double_precision
@@ -78,7 +78,7 @@ endif
 # This is a shortcut to alleviate errors when parsing parameter inputs in soltab.
 ifeq ($(detected_OS), Windows)
 	ifeq ($(FC), gfortran)
-		FFLAGS = $(OPTLEVEL) -fno-second-underscore -fallow-argument-mismatch
+		FFLAGS = -freal-4-real-8 $(OPTLEVEL) -fno-second-underscore -fallow-argument-mismatch
 	endif
 else
 	ifeq ($(FC), gfortran)
@@ -99,7 +99,7 @@ endif
 
 ifeq ($(detected_OS), Windows)
 	ifeq ($(CC), gcc)
-		CFLAGS = $(OPTLEVEL) -D$(ARC) -D_UF -Wall
+		CFLAGS = -Dfloat=double $(OPTLEVEL) -D$(ARC) -D_UF -Wall
 	endif
 else
 	ifeq ($(CC), gcc)
diff --git a/test_data/generate/conftest.py b/test_data/generate/conftest.py
index bf78113e..83a4fcc3 100644
--- a/test_data/generate/conftest.py
+++ b/test_data/generate/conftest.py
@@ -34,7 +34,7 @@ def pytest_addoption(parser):
 def exe():
     platform = sys.platform.lower()
     if platform == "win32":
-        exe_name = "prms_win_ifort_mixed_prec.exe"
+        exe_name = "prms_win_gfort_dbl_prec.exe"
     elif platform == "darwin":
         if processor() == "arm":
             exe_name = "prms_mac_m1_ifort_dbl_prec"