diff --git a/src/pack_unpack.c b/src/pack_unpack.c
index fc98df4..ec04bc3 100644
--- a/src/pack_unpack.c
+++ b/src/pack_unpack.c
@@ -261,7 +261,7 @@ static json_t *pack_object(scanner_t *s, va_list *ap)
                 jsonp_free(key);
 
             if(valueOptional != '*') {
-                set_error(s, "<args>", json_error_null_value, "NULL object value\n");
+                set_error(s, "<args>", json_error_null_value, "NULL object value");
                 s->has_error = 1;
             }
 
@@ -396,11 +396,47 @@ static json_t *pack_object_inter(scanner_t *s, va_list *ap, int need_incref)
             break;
     }
 
-    set_error(s, "<args>", json_error_null_value, "NULL object key");
+    set_error(s, "<args>", json_error_null_value, "NULL object");
     s->has_error = 1;
     return NULL;
 }
 
+static json_t *pack_integer(scanner_t *s, json_int_t value)
+{
+    json_t *json = json_integer(value);
+
+    if (!json) {
+        set_error(s, "<internal>", json_error_out_of_memory, "Out of memory");
+        s->has_error = 1;
+    }
+
+    return json;
+}
+
+static json_t *pack_real(scanner_t *s, double value)
+{
+    /* Allocate without setting value so we can identify OOM error. */
+    json_t *json = json_real(0.0);
+
+    if (!json) {
+        set_error(s, "<internal>", json_error_out_of_memory, "Out of memory");
+        s->has_error = 1;
+
+        return NULL;
+    }
+
+    if (json_real_set(json, value)) {
+        json_decref(json);
+
+        set_error(s, "<args>", json_error_numeric_overflow, "Invalid floating point value");
+        s->has_error = 1;
+
+        return NULL;
+    }
+
+    return json;
+}
+
 static json_t *pack(scanner_t *s, va_list *ap)
 {
     switch(token(s)) {
@@ -420,13 +456,13 @@ static json_t *pack(scanner_t *s, va_list *ap)
             return va_arg(*ap, int) ? json_true() : json_false();
 
         case 'i': /* integer from int */
-            return json_integer(va_arg(*ap, int));
+            return pack_integer(s, va_arg(*ap, int));
 
         case 'I': /* integer from json_int_t */
-            return json_integer(va_arg(*ap, json_int_t));
+            return pack_integer(s, va_arg(*ap, json_int_t));
 
         case 'f': /* real */
-            return json_real(va_arg(*ap, double));
+            return pack_real(s, va_arg(*ap, double));
 
         case 'O': /* a json_t object; increments refcount */
             return pack_object_inter(s, ap, 1);
diff --git a/test/suites/api/test_pack.c b/test/suites/api/test_pack.c
index 7e1c0b5..ab3aa91 100644
--- a/test/suites/api/test_pack.c
+++ b/test/suites/api/test_pack.c
@@ -15,8 +15,39 @@
 #include <string.h>
 #include <jansson.h>
 #include <stdio.h>
+#include <math.h>
 #include "util.h"
 
+#ifdef INFINITY
+// This test triggers "warning C4756: overflow in constant arithmetic"
+// in Visual Studio. This warning is triggered here by design, so disable it.
+// (This can only be done on function level so we keep these tests separate)
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning (disable: 4756)
+#endif
+static void test_inifity()
+{
+    json_error_t error;
+
+    if (json_pack_ex(&error, 0, "f", INFINITY))
+       fail("json_pack infinity incorrectly succeeded");
+    check_error(json_error_numeric_overflow, "Invalid floating point value", "<args>", 1, 1, 1);
+
+    if (json_pack_ex(&error, 0, "[f]", INFINITY))
+       fail("json_pack infinity array element incorrectly succeeded");
+    check_error(json_error_numeric_overflow, "Invalid floating point value", "<args>", 1, 2, 2);
+
+    if (json_pack_ex(&error, 0, "{s:f}", "key", INFINITY))
+       fail("json_pack infinity object value incorrectly succeeded");
+    check_error(json_error_numeric_overflow, "Invalid floating point value", "<args>", 1, 4, 4);
+
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+}
+#endif // INFINITY
+
 static void run_tests()
 {
     json_t *value;
@@ -313,6 +344,25 @@ static void run_tests()
         fail("json_pack array optional failed");
     json_decref(value);
 
+#ifdef NAN
+    /* Invalid float values */
+    if (json_pack_ex(&error, 0, "f", NAN))
+        fail("json_pack NAN incorrectly succeeded");
+    check_error(json_error_numeric_overflow, "Invalid floating point value", "<args>", 1, 1, 1);
+
+    if (json_pack_ex(&error, 0, "[f]", NAN))
+       fail("json_pack NAN array element incorrectly succeeded");
+    check_error(json_error_numeric_overflow, "Invalid floating point value", "<args>", 1, 2, 2);
+
+    if (json_pack_ex(&error, 0, "{s:f}", "key", NAN))
+       fail("json_pack NAN object value incorrectly succeeded");
+    check_error(json_error_numeric_overflow, "Invalid floating point value", "<args>", 1, 4, 4);
+#endif
+
+#ifdef INFINITY
+    test_inifity();
+#endif
+
     /* Whitespace; regular string */
     value = json_pack(" s\t ", "test");
     if(!json_is_string(value) || strcmp("test", json_string_value(value)))
@@ -439,9 +489,9 @@ static void run_tests()
 
     if(json_pack_ex(&error, 0, "{s:o}", "foo", NULL))
         fail("json_pack failed to catch nullable object");
-    check_error(json_error_null_value, "NULL object key", "<args>", 1, 4, 4);
+    check_error(json_error_null_value, "NULL object", "<args>", 1, 4, 4);
 
     if(json_pack_ex(&error, 0, "{s:O}", "foo", NULL))
         fail("json_pack failed to catch nullable incref object");
-    check_error(json_error_null_value, "NULL object key", "<args>", 1, 4, 4);
+    check_error(json_error_null_value, "NULL object", "<args>", 1, 4, 4);
 }