diff --git a/src/procmap.cpp b/src/procmap.cpp
index 9d1ed83e73..8207b61f4c 100644
--- a/src/procmap.cpp
+++ b/src/procmap.cpp
@@ -301,7 +301,8 @@ void ProcMap::custom_grid(char *cfile, int nprocs,
   MPI_Bcast(&n,1,MPI_INT,0,world);
   MPI_Bcast(line,n,MPI_CHAR,0,world);
 
-  sscanf(line,"%d %d %d",&procgrid[0],&procgrid[1],&procgrid[2]);
+  int rv = sscanf(line,"%d %d %d",&procgrid[0],&procgrid[1],&procgrid[2]);
+  if (rv != 3) error->all(FLERR,"Processors custom grid file is inconsistent");
 
   int flag = 0;
   if (procgrid[0]*procgrid[1]*procgrid[2] != nprocs) flag = 1;
@@ -320,8 +321,10 @@ void ProcMap::custom_grid(char *cfile, int nprocs,
     for (int i = 0; i < nprocs; i++) {
       if (!fgets(line,MAXLINE,fp))
         error->one(FLERR,"Unexpected end of custom file");
-      sscanf(line,"%d %d %d %d",
-             &cmap[i][0],&cmap[i][1],&cmap[i][2],&cmap[i][3]);
+      rv = sscanf(line,"%d %d %d %d",
+                  &cmap[i][0],&cmap[i][1],&cmap[i][2],&cmap[i][3]);
+      if (rv != 4)
+        error->one(FLERR,"Processors custom grid file is inconsistent");
     }
     fclose(fp);
   }
diff --git a/src/universe.cpp b/src/universe.cpp
index f078590103..dba31f8b76 100644
--- a/src/universe.cpp
+++ b/src/universe.cpp
@@ -114,19 +114,19 @@ void Universe::reorder(char *style, char *arg)
       // read nprocs lines
       // uni2orig = inverse mapping
 
-      int me_orig,me_new;
-      sscanf(line,"%d %d",&me_orig,&me_new);
+      int me_orig,me_new,rv;
+      rv = sscanf(line,"%d %d",&me_orig,&me_new);
       if (me_orig < 0 || me_orig >= nprocs ||
-          me_new < 0 || me_new >= nprocs)
+          me_new < 0 || me_new >= nprocs || rv != 2)
         error->one(FLERR,"Invalid entry in -reorder file");
       uni2orig[me_new] = me_orig;
 
       for (int i = 1; i < nprocs; i++) {
         if (!fgets(line,MAXLINE,fp))
           error->one(FLERR,"Unexpected end of -reorder file");
-        sscanf(line,"%d %d",&me_orig,&me_new);
+        rv = sscanf(line,"%d %d",&me_orig,&me_new);
         if (me_orig < 0 || me_orig >= nprocs ||
-            me_new < 0 || me_new >= nprocs)
+            me_new < 0 || me_new >= nprocs || rv != 2)
           error->one(FLERR,"Invalid entry in -reorder file");
         uni2orig[me_new] = me_orig;
       }
diff --git a/src/variable.cpp b/src/variable.cpp
index ea7f3044d7..63a425bcf5 100644
--- a/src/variable.cpp
+++ b/src/variable.cpp
@@ -5162,8 +5162,8 @@ int VarReader::read_peratom()
     for (i = 0; i < nchunk; i++) {
       next = strchr(buf,'\n');
       *next = '\0';
-      sscanf(buf,TAGINT_FORMAT " %lg",&tag,&value);
-      if (tag <= 0 || tag > map_tag_max)
+      int rv = sscanf(buf,TAGINT_FORMAT " %lg",&tag,&value);
+      if (tag <= 0 || tag > map_tag_max || rv != 2)
         error->one(FLERR,"Invalid atom ID in variable file");
       if ((m = atom->map(tag)) >= 0) vstore[m] = value;
       buf = next + 1;