diff --git a/pipi/context.c b/pipi/context.c
index ad4be46..0c0f6d9 100644
--- a/pipi/context.c
+++ b/pipi/context.c
@@ -121,7 +121,7 @@ int pipi_command(pipi_context_t *ctx, char const *cmd, ...)
         arg = va_arg(ap, char const *);
         va_end(ap);
         src = ctx->images[ctx->nimages - 1];
-        dst = pipi_gaussian_blur(src, atoi(arg));
+        dst = pipi_gaussian_blur(src, atof(arg));
         if(dst == NULL)
             return -1;
         pipi_free(src);