diff --git a/libnczarr/zfilter.c b/libnczarr/zfilter.c
index a4ca1d358..58bb0984d 100644
--- a/libnczarr/zfilter.c
+++ b/libnczarr/zfilter.c
@@ -1508,7 +1508,8 @@ memset(plugin,0,sizeof(NCZ_Plugin));
 static int
 pluginnamecheck(const char* name)
 {
-   size_t i,count,len;
+   size_t count,len;
+   long i;
    const char* p;
    if(name == NULL) return 0;
    /* get basename */
@@ -1516,7 +1517,7 @@ pluginnamecheck(const char* name)
    if(p != NULL) name = (p+1);
    len = strlen(name);
    if(len == 0) return 0;
-   i = len-1;
+   i = (long)(len-1);
    count = 1;
    p = name+i;
    for(;i>=0;i--,count++,p--) {
diff --git a/ncdump/ncfilteravail.c b/ncdump/ncfilteravail.c
index b7e937627..d8ee342f6 100644
--- a/ncdump/ncfilteravail.c
+++ b/ncdump/ncfilteravail.c
@@ -89,7 +89,7 @@ getformat(const char* sformat)
 
 
 static int
-makeurl(struct Options* faoptions)
+makeurl(struct Options* faopt)
 {
     int stat = NC_NOERR;
     int format;
@@ -101,7 +101,7 @@ makeurl(struct Options* faoptions)
 #else
     pid = (int)getpid();
 #endif
-    switch (format = getformat(faoptions->format)) {
+    switch (format = getformat(faopt->format)) {
     case NC_FORMATX_NC4:
 	snprintf(url,sizeof(url),"tmp_%d.nc",pid);
 	break;
@@ -110,23 +110,23 @@ makeurl(struct Options* faoptions)
 	break;
     default: stat = NC_EINVAL; break;
     }
-    if(stat == NC_NOERR) faoptions->url = strdup(url);
+    if(stat == NC_NOERR) faopt->url = strdup(url);
     return stat;
 }
 
 static int
-makefilterid(struct Options* faoptions)
+makefilterid(struct Options* faopt)
 {
     int stat = NC_NOERR;
     const struct Filter* f = NULL;
     for(f=known_filters;f->name;f++) {
-        if(strcmp(f->name,faoptions->filtername)==0) {
-	    faoptions->filterid = f->id;
+        if(strcmp(f->name,faopt->filtername)==0) {
+	    faopt->filterid = f->id;
 	    goto done;
 	}
     }
     /* See if it is a number */
-    if(1!=sscanf(faoptions->filtername,"%u",&faoptions->filterid))
+    if(1!=sscanf(faopt->filtername,"%u",&faopt->filterid))
 	{stat = NC_EINVAL; goto done;}
 done:
     return stat;
diff --git a/plugins/H5Zblosc.c b/plugins/H5Zblosc.c
index b4fba83d0..06afc4c71 100755
--- a/plugins/H5Zblosc.c
+++ b/plugins/H5Zblosc.c
@@ -469,7 +469,7 @@ NCZ_blosc_modify_parameters(int ncid, int varid, size_t* vnparamsp, unsigned** v
         {stat = NC_EFILTER; goto done;}
     nparams = 7;
 
-    if(vnparams > 0 && vparams == NULL)
+    if(vparams == NULL)
         {stat = NC_EFILTER; goto done;}
 
     if(wnparamsp == NULL || wparamsp == NULL)