diff --git a/src/frontend/breakp.c b/src/frontend/breakp.c
index 8fd822eef..eb20980fc 100644
--- a/src/frontend/breakp.c
+++ b/src/frontend/breakp.c
@@ -241,7 +241,7 @@ com_iplot(wordlist *wl)
         return;
     }
 
-    struct dbcomm *d, *td, *currentdb = NULL;
+    struct dbcomm *d, *td = NULL, *currentdb = NULL;
     double         window = 0.0;
 #ifdef XSPICE
     int            event_auto_incr = 0;
@@ -311,7 +311,7 @@ com_iplot(wordlist *wl)
 
         /* Chain in expected order. */
 
-        if (currentdb)
+        if (currentdb && td)
             td->db_also = d;
         else
             currentdb = d;
diff --git a/src/frontend/inpcom.c b/src/frontend/inpcom.c
index e13b10cd5..8e692bac9 100644
--- a/src/frontend/inpcom.c
+++ b/src/frontend/inpcom.c
@@ -1491,6 +1491,7 @@ static struct inp_read_t inp_read(FILE* fp, int call_depth, const char* dir_name
             struct card* newcard;
 
             struct compat tmpcomp;
+            memset(&tmpcomp, 0, sizeof(tmpcomp));
             bool compset = FALSE;
 
             /* special treatment of special .inc commands */
diff --git a/src/frontend/plotting/graf.c b/src/frontend/plotting/graf.c
index 2e29e07fa..6a6ca5f57 100644
--- a/src/frontend/plotting/graf.c
+++ b/src/frontend/plotting/graf.c
@@ -84,7 +84,7 @@ int gr_init(double *xlims, double *ylims, /* The size of the screen. */
         const char *commandline, /* For xi_zoomdata() */
         int prevgraph)                /* plot id, if started from a previous plot*/
 {
-    GRAPH    *graph, *pgraph;
+    GRAPH    *graph, *pgraph = NULL;
     wordlist *wl;
 
     NG_IGNORE(nplots);
@@ -182,7 +182,7 @@ int gr_init(double *xlims, double *ylims, /* The size of the screen. */
     }
 
     /* restore data from previous graph, e.g. for zooming */
-    if (prevgraph > 0) {
+    if (prevgraph > 0 && pgraph) {
         int i;
 
         /* transmit colors */
@@ -1359,7 +1359,7 @@ void gr_iplot(struct plot *plot)
                     struct dbcomm *dd;
                     int            dup = 0;
 #ifdef XSPICE
-                    char          *offp, save_sign;
+                    char          *offp, save_sign = '\0';
 #endif
 
                     if (dc->db_nodename1 == NULL)
diff --git a/src/spicelib/parser/inp2n.c b/src/spicelib/parser/inp2n.c
index b01d8b44c..2593c7465 100644
--- a/src/spicelib/parser/inp2n.c
+++ b/src/spicelib/parser/inp2n.c
@@ -30,7 +30,7 @@ void INP2N(CKTcircuit *ckt, INPtables *tab, struct card *current) {
   GENinstance *fast;      /* Pointer to the actual instance. */
   int          waslead;   /* Funny unlabeled number was found. */
   double       leadval;   /* Value of unlabeled number. */
-  INPmodel    *thismodel; /* Pointer to model description for user's model. */
+  INPmodel    *thismodel = NULL; /* Pointer to model description for user's model. */
   GENmodel    *mdfast;    /* Pointer to the actual model. */
   IFdevice    *dev;
   CKTnode     *node;