diff --git a/src/spicelib/devices/isrc/isrcdefs.h b/src/spicelib/devices/isrc/isrcdefs.h
index b761a2e33..0c21e56bb 100644
--- a/src/spicelib/devices/isrc/isrcdefs.h
+++ b/src/spicelib/devices/isrc/isrcdefs.h
@@ -138,7 +138,8 @@ typedef struct sISRCmodel {
 
 /* source types */
 
-#ifndef PULSE
+#ifndef PULSE_FUN_TYPES
+#define PULSE_FUN_TYPES
 #define PULSE 1
 #define SINE 2
 #define EXP 3
@@ -148,7 +149,7 @@ typedef struct sISRCmodel {
 #define TRNOISE 7
 #define TRRANDOM 8
 #define EXTERNAL 9
-#endif /*PULSE*/
+#endif
 
 /* device parameters */
 #define ISRC_DC 1
diff --git a/src/spicelib/devices/vsrc/vsrcdefs.h b/src/spicelib/devices/vsrc/vsrcdefs.h
index 773526296..3e3a188a5 100644
--- a/src/spicelib/devices/vsrc/vsrcdefs.h
+++ b/src/spicelib/devices/vsrc/vsrcdefs.h
@@ -164,7 +164,8 @@ typedef struct sVSRCmodel {
 } VSRCmodel;
 
 /* source function types (shared with current sources) */
-#ifndef PULSE
+#ifndef PULSE_FUN_TYPES
+#define PULSE_FUN_TYPES
 #define PULSE 1
 #define SINE 2
 #define EXP 3
@@ -174,7 +175,7 @@ typedef struct sVSRCmodel {
 #define TRNOISE 7
 #define TRRANDOM 8
 #define EXTERNAL 9
-#endif /*PULSE*/
+#endif
 
 /* device parameters */
 #define VSRC_DC 1