diff --git a/Source/m_misc.c b/Source/m_misc.c
index e2417c46..4614624b 100644
--- a/Source/m_misc.c
+++ b/Source/m_misc.c
@@ -2221,7 +2221,7 @@ typedef unsigned long dword_t;
 typedef long     long_t;
 typedef unsigned char ubyte_t;
 
-#ifdef _MSC_VER
+#ifdef _WIN32
 #pragma pack(push, 1)
 #endif
 
@@ -2249,7 +2249,7 @@ typedef struct tagBITMAPINFOHEADER
   dword_t biClrImportant;
 } __attribute__ ((packed)) BITMAPINFOHEADER;
 
-#ifdef _MSC_VER
+#ifdef _WIN32
 #pragma pack(pop)
 #endif
 
diff --git a/Source/p_spec.c b/Source/p_spec.c
index 87c5fa1b..8f25fb1b 100644
--- a/Source/p_spec.c
+++ b/Source/p_spec.c
@@ -69,7 +69,7 @@ typedef struct
   int         speed;
 } anim_t;
 
-#ifdef _MSC_VER
+#ifdef _WIN32
 #pragma pack(push, 1)
 #endif
 
@@ -84,7 +84,7 @@ typedef struct
   int  speed;
 } __attribute__ ((packed)) animdef_t; //jff 3/23/98 pack to read from memory
 
-#ifdef _MSC_VER
+#ifdef _WIN32
 #pragma pack(pop)
 #endif
 
diff --git a/Source/p_spec.h b/Source/p_spec.h
index a09f6d8d..fb9bef26 100644
--- a/Source/p_spec.h
+++ b/Source/p_spec.h
@@ -514,7 +514,7 @@ typedef enum
 
 // switch animation structure type
 
-#ifdef _MSC_VER
+#ifdef _WIN32
 #pragma pack(push, 1)
 #endif
 
@@ -525,7 +525,7 @@ typedef struct
   short episode;
 } __attribute__ ((packed)) switchlist_t; //jff 3/23/98 pack to read from memory
 
-#ifdef _MSC_VER
+#ifdef _WIN32
 #pragma pack(pop)
 #endif
 
diff --git a/Source/w_wad.h b/Source/w_wad.h
index 2a8a362f..a6c58ef5 100644
--- a/Source/w_wad.h
+++ b/Source/w_wad.h
@@ -34,7 +34,7 @@
 //
 
 // haleyjd 01/21/05: these structs must be packed
-#ifdef _MSC_VER
+#ifdef _WIN32
 #pragma pack(push, 1)
 #endif
 
@@ -52,7 +52,7 @@ typedef struct
   char name[8];
 } filelump_t;
 
-#ifdef _MSC_VER
+#ifdef _WIN32
 #pragma pack(pop)
 #endif