diff --git a/os2.c b/os2.c
index 064dac66bd..2764c3454e 100644
--- a/os2.c
+++ b/os2.c
@@ -392,10 +392,19 @@ StringID FiosGetDescText(const char **path)
 
 void FiosMakeSavegameName(char *buf, const char *name)
 {
+	const char* extension;
+	const char* period;
+
 	if (_game_mode == GM_EDITOR)
-		sprintf(buf, "%s\\%s.scn", _fios_path, name);
+		extension = ".scn";
 	else
-		sprintf(buf, "%s\\%s.sav", _fios_path, name);
+		extension = ".sav";
+
+	// Don't append the extension, if it is already there
+	period = strrchr(name, '.');
+	if (period != NULL && strcasecmp(period, extension) == 0) extension = "";
+
+	sprintf(buf, "%s\\%s%s", _fios_path, name, extension);
 }
 
 void FiosDelete(const char *name)
diff --git a/unix.c b/unix.c
index 529c57d9e6..d24255b8ba 100644
--- a/unix.c
+++ b/unix.c
@@ -324,10 +324,19 @@ StringID FiosGetDescText(const char **path)
 
 void FiosMakeSavegameName(char *buf, const char *name)
 {
+	const char* extension;
+	const char* period;
+
 	if (_game_mode == GM_EDITOR)
-		sprintf(buf, "%s/%s.scn", _fios_path, name);
+		extension = ".scn";
 	else
-		sprintf(buf, "%s/%s.sav", _fios_path, name);
+		extension = ".sav";
+
+	// Don't append the extension, if it is already there
+	period = strrchr(name, '.');
+	if (period != NULL && strcasecmp(period, extension) == 0) extension = "";
+
+	sprintf(buf, "%s/%s%s", _fios_path, name, extension);
 }
 
 void FiosDelete(const char *name)
diff --git a/win32.c b/win32.c
index 8f1e124d3c..7003e7aeff 100644
--- a/win32.c
+++ b/win32.c
@@ -1848,10 +1848,19 @@ StringID FiosGetDescText(const char **path)
 
 void FiosMakeSavegameName(char *buf, const char *name)
 {
+	const char* extension;
+	const char* period;
+
 	if (_game_mode == GM_EDITOR)
-		sprintf(buf, "%s\\%s.scn", _fios_path, name);
+		extension = ".scn";
 	else
-		sprintf(buf, "%s\\%s.sav", _fios_path, name);
+		extension = ".sav";
+
+	// Don't append the extension, if it is already there
+	period = strrchr(name, '.');
+	if (period != NULL && strcasecmp(period, extension) == 0) extension = "";
+
+	sprintf(buf, "%s\\%s%s", _fios_path, name, extension);
 }
 
 void FiosDelete(const char *name)