diff --git a/display/d.graph/do_graph.c b/display/d.graph/do_graph.c
index 5b1e13deac0..def7b9b4477 100644
--- a/display/d.graph/do_graph.c
+++ b/display/d.graph/do_graph.c
@@ -50,7 +50,7 @@ int set_graph_stuff(void)
 int set_text_size(void)
 {
     if (hsize >= 0. && vsize >= 0. && hsize <= 100. && vsize <= 100.) {
-        D_text_size(hsize * xincr, vsize * yincr);
+        D_text_size((double)hsize * xincr, (double)vsize * yincr);
         G_debug(3, "text size initialized to [%.1f,%.1f]", hsize * xincr,
                 vsize * yincr);
     }
@@ -201,7 +201,7 @@ int do_size(const char *str)
     if (xper < 0. || yper < 0. || xper > 100. || yper > 100.)
         return (-1);
 
-    D_text_size(xper * xincr, yper * yincr);
+    D_text_size((double)xper * xincr, (double)yper * yincr);
     G_debug(3, "text size set to [%.1f,%.1f]", xper * xincr, yper * yincr);
 
     return (0);
diff --git a/display/d.legend/draw.c b/display/d.legend/draw.c
index d3353589d4d..47d7df32501 100644
--- a/display/d.legend/draw.c
+++ b/display/d.legend/draw.c
@@ -1098,7 +1098,7 @@ void draw(const char *map_name, int maptype, int color, int thin, int lines,
                             0.81)); /* ?? txsiz*.81=actual text width. */
             if (ScaleFactor < 1.0) {
                 txsiz = txsiz * ScaleFactor;
-                dots_per_line = (int)floor(dots_per_line * ScaleFactor);
+                dots_per_line = (int)floor((double)dots_per_line * ScaleFactor);
             }
         }
 
diff --git a/imagery/i.segment/flag.c b/imagery/i.segment/flag.c
index b638ec9b68e..3cfed9ec2ff 100644
--- a/imagery/i.segment/flag.c
+++ b/imagery/i.segment/flag.c
@@ -20,7 +20,7 @@ FLAG *flag_create(int nrows, int ncols)
     if (!new_flag->array)
         G_fatal_error(_("Out of memory!"));
 
-    temp = (unsigned char *)G_malloc(nrows * new_flag->leng *
+    temp = (unsigned char *)G_malloc((size_t)nrows * new_flag->leng *
                                      sizeof(unsigned char));
 
     if (!temp)
diff --git a/raster3d/r3.in.v5d/main.c b/raster3d/r3.in.v5d/main.c
index 72c8a4a3214..f750892ff7e 100644
--- a/raster3d/r3.in.v5d/main.c
+++ b/raster3d/r3.in.v5d/main.c
@@ -117,11 +117,11 @@ void convert(char *openFile, RASTER3D_Region *region, int convertNull,
             res_r = v5d.ProjArgs[2];
             res_c = v5d.ProjArgs[3];
             res_l = v5d.VertArgs[1];
-            region->south = region->north - region->rows * res_r;
+            region->south = region->north - (double)region->rows * res_r;
             region->west = v5d.ProjArgs[1];
-            region->east = region->west + region->cols * res_c;
+            region->east = region->west + (double)region->cols * res_c;
             region->bottom = v5d.VertArgs[0];
-            region->top = region->bottom + region->depths * res_l;
+            region->top = region->bottom + (double)region->depths * res_l;
 
             data1 = (float *)G_malloc(nrncnl * sizeof(float));
             if (!data1)
diff --git a/raster3d/r3.out.v5d/main.c b/raster3d/r3.out.v5d/main.c
index a6be34e2469..23d01b8fe7f 100644
--- a/raster3d/r3.out.v5d/main.c
+++ b/raster3d/r3.out.v5d/main.c
@@ -195,7 +195,7 @@ void convert(char *fileout, int rows, int cols, int depths, int trueCoords)
 
     /****************/
 
-    g = (float *)G_malloc(rows * cols * Nl[0] * sizeof(float));
+    g = (float *)G_malloc((size_t)rows * cols * Nl[0] * sizeof(float));
     d1p = &d1;
     f1p = (float *)&d1;
     cnt = 0;
diff --git a/vector/v.vol.rst/user3.c b/vector/v.vol.rst/user3.c
index bc7fd69511f..76c802b5322 100644
--- a/vector/v.vol.rst/user3.c
+++ b/vector/v.vol.rst/user3.c
@@ -253,7 +253,7 @@ int COGRR1(double x_or, double y_or, double z_or, int n_rows, int n_cols,
        c normalization
        c
      */
-    offset1 = nsizr * nsizc;
+    offset1 = (off_t)nsizr * nsizc;
 
     stepix = ew_res / dnorm;
     stepiy = ns_res / dnorm;
diff --git a/visualization/ximgview/color.c b/visualization/ximgview/color.c
index f24c59367f6..2a7b91cfc95 100644
--- a/visualization/ximgview/color.c
+++ b/visualization/ximgview/color.c
@@ -142,8 +142,8 @@ static int try_get_colors(Colormap cmap, int nr, int ng, int nb)
     int n_pixels;
     int r, g, b;
 
-    xpixels = (unsigned long *)G_realloc(xpixels,
-                                         nr * ng * nb * sizeof(unsigned long));
+    xpixels = (unsigned long *)G_realloc(xpixels, (size_t)nr * ng * nb *
+                                                      sizeof(unsigned long));
     n_pixels = 0;
 
     xcolor.flags = DoRed | DoGreen | DoBlue;