diff --git a/src/rtkcmn.c b/src/rtkcmn.c
index bb4ac760c..3bb325903 100644
--- a/src/rtkcmn.c
+++ b/src/rtkcmn.c
@@ -2698,33 +2698,44 @@ extern pcv_t *searchpcv(int sat, const char *type, gtime_t time,
 *-----------------------------------------------------------------------------*/
 extern void readpos(const char *file, const char *rcv, double *pos)
 {
-    static double poss[2048][3];
-    static char stas[2048][16];
-    FILE *fp;
-    int i,j,len,np=0;
-    char buff[256],str[256];
+  trace(3, "readpos: file=%s\n", file);
 
-    trace(3,"readpos: file=%s\n",file);
+  FILE *fp = fopen(file, "r");
+  if (fp == NULL) {
+    fprintf(stderr, "reference position file open error : %s\n", file);
+    return;
+  }
 
-    if (!(fp=fopen(file,"r"))) {
-        fprintf(stderr,"reference position file open error : %s\n",file);
-        return;
-    }
-    while (np<2048&&fgets(buff,sizeof(buff),fp)) {
-        if (buff[0]=='%'||buff[0]=='#') continue;
-        if (sscanf(buff,"%lf %lf %lf %255s",&poss[np][0],&poss[np][1],&poss[np][2],
-                   str)<4) continue;
-        sprintf(stas[np++],"%.15s",str);
-    }
-    fclose(fp);
-    len=(int)strlen(rcv);
-    for (i=0;i<np;i++) {
-        if (strncmp(stas[i],rcv,len)) continue;
-        for (j=0;j<3;j++) pos[j]=poss[i][j];
-        pos[0]*=D2R; pos[1]*=D2R;
-        return;
-    }
-    pos[0]=pos[1]=pos[2]=0.0;
+  size_t maxp = 2048;
+  double (*poss)[3] = malloc(maxp * sizeof(*poss));
+  char (*stas)[16] = malloc(maxp * sizeof(*stas));
+  if (poss == NULL || stas == NULL) {
+    trace(1, "readpos malloc error\n");
+    goto done;
+  }
+
+  unsigned np = 0;
+  char buff[256];
+  while (np < maxp && fgets(buff, sizeof(buff), fp)) {
+    if (buff[0] == '%' || buff[0] == '#') continue;
+    char str[256];
+    if (sscanf(buff, "%lf %lf %lf %255s", &poss[np][0], &poss[np][1], &poss[np][2], str) < 4)
+      continue;
+    snprintf(stas[np++], sizeof(stas[0]), "%.15s", str);
+  }
+  fclose(fp);
+  size_t len = strlen(rcv);
+  for (unsigned i = 0; i < np; i++) {
+    if (strncmp(stas[i], rcv, len)) continue;
+    for (unsigned j = 0; j < 3; j++) pos[j] = poss[i][j];
+    pos[0] *= D2R;
+    pos[1] *= D2R;
+    goto done;
+  }
+  pos[0] = pos[1] = pos[2] = 0.0;
+done:
+  free(poss);
+  free(stas);
 }
 /* read blq record -----------------------------------------------------------*/
 static int readblqrecord(FILE *fp, double odisp[2][11][3])