diff --git a/src/include/ngspice/macros.h b/src/include/ngspice/macros.h
index 284edab31..c485517cf 100644
--- a/src/include/ngspice/macros.h
+++ b/src/include/ngspice/macros.h
@@ -43,11 +43,12 @@
 #define NIL(type) ((type *)0) 
 #define ABORT() fflush(stderr);fflush(stdout);abort();
 
-#define MERROR(CODE,MESSAGE)	{			      \
-	errMsg = TMALLOC(char, strlen(MESSAGE) + 1);     \
-	strcpy(errMsg, (MESSAGE));			      \
-	return (CODE);					      \
-	}
+#define MERROR(CODE, MESSAGE) \
+    do {                                                      \
+        errMsg = TMALLOC(char, strlen(MESSAGE) + 1);          \
+        strcpy(errMsg, (MESSAGE));                            \
+        return (CODE);                                        \
+    } while(0)
 
 #define	NEW(TYPE)	(TMALLOC(TYPE, 1))
 #define	NEWN(TYPE,COUNT) (TMALLOC(TYPE, COUNT))
diff --git a/src/spicelib/analysis/pzan.c b/src/spicelib/analysis/pzan.c
index 6117f67df..0e1655d09 100644
--- a/src/spicelib/analysis/pzan.c
+++ b/src/spicelib/analysis/pzan.c
@@ -94,7 +94,7 @@ PZinit(CKTcircuit *ckt)
 		i = CKTtypelook("LTRA");
     }
     if (i != -1 && ckt->CKThead[i] != NULL)
-	MERROR(E_XMISSIONLINE, "Transmission lines not supported")
+	MERROR(E_XMISSIONLINE, "Transmission lines not supported");
 
     job->PZpoleList = NULL;
     job->PZzeroList = NULL;
@@ -102,19 +102,19 @@ PZinit(CKTcircuit *ckt)
     job->PZnZeros = 0;
 
     if (job->PZin_pos == job->PZin_neg)
-	MERROR(E_SHORT, "Input is shorted")
+	MERROR(E_SHORT, "Input is shorted");
 
     if (job->PZout_pos == job->PZout_neg)
-	MERROR(E_SHORT, "Output is shorted")
+	MERROR(E_SHORT, "Output is shorted");
 
     if (job->PZin_pos == job->PZout_pos
         && job->PZin_neg == job->PZout_neg
 	&& job->PZinput_type == PZ_IN_VOL)
-	MERROR(E_INISOUT, "Transfer function is unity")
+	MERROR(E_INISOUT, "Transfer function is unity");
     else if (job->PZin_pos == job->PZout_neg
         && job->PZin_neg == job->PZout_pos
 	&& job->PZinput_type == PZ_IN_VOL)
-	MERROR(E_INISOUT, "Transfer function is -1")
+	MERROR(E_INISOUT, "Transfer function is -1");
 
     return(OK);
 }