diff --git a/src/spicelib/devices/isrc/isrcdefs.h b/src/spicelib/devices/isrc/isrcdefs.h
index 4e8533aed..14e373ea8 100644
--- a/src/spicelib/devices/isrc/isrcdefs.h
+++ b/src/spicelib/devices/isrc/isrcdefs.h
@@ -87,7 +87,8 @@ typedef struct sISRCmodel {
 
 /* source types */
 
-#ifndef PULSE
+#ifndef PULSE_FUN_TYPES
+#define PULSE_FUN_TYPES
 #define PULSE 1
 #define SINE 2
 #define EXP 3
@@ -97,7 +98,7 @@ 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 0c5cfeddb..0a7a707df 100644
--- a/src/spicelib/devices/vsrc/vsrcdefs.h
+++ b/src/spicelib/devices/vsrc/vsrcdefs.h
@@ -94,7 +94,8 @@ 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
@@ -104,7 +105,7 @@ typedef struct sVSRCmodel {
 #define TRNOISE 7
 #define TRRANDOM 8
 #define EXTERNAL 9
-#endif /*PULSE*/
+#endif
 
 /* device parameters */
 #define VSRC_DC 1