diff --git a/lib/os/cbprintf_nano.c b/lib/os/cbprintf_nano.c
index bfe44925c91..1ccd8047d68 100644
--- a/lib/os/cbprintf_nano.c
+++ b/lib/os/cbprintf_nano.c
@@ -174,20 +174,40 @@ start:
 			uint_value_type d;
 
 			if (length_mod == 'z') {
-				d = va_arg(ap, ssize_t);
-			} else if (length_mod == 'l') {
-				d = va_arg(ap, long);
-			} else if (length_mod == 'L') {
-				long long lld = va_arg(ap, long long);
-
-				if (sizeof(int_value_type) < 8U &&
-				    lld != (int_value_type) lld) {
-					data = "ERR";
-					data_len = 3;
-					precision = 0;
-					break;
+				if (*fmt == 'u') {
+					d = va_arg(ap, size_t);
+				} else {
+					d = va_arg(ap, ssize_t);
+				}
+			} else if (length_mod == 'l') {
+				if (*fmt == 'u') {
+					d = va_arg(ap, unsigned long);
+				} else {
+					d = va_arg(ap, long);
+				}
+			} else if (length_mod == 'L') {
+				if (*fmt == 'u') {
+					unsigned long long llu =
+						va_arg(ap, unsigned long long);
+
+					if (llu != (uint_value_type) llu) {
+						data = "ERR";
+						data_len = 3;
+						precision = 0;
+						break;
+					}
+					d = (uint_value_type) llu;
+				} else {
+					long long lld = va_arg(ap, long long);
+
+					if (lld != (int_value_type) lld) {
+						data = "ERR";
+						data_len = 3;
+						precision = 0;
+						break;
+					}
+					d = (int_value_type) lld;
 				}
-				d = (uint_value_type) lld;
 			} else if (*fmt == 'u') {
 				d = va_arg(ap, unsigned int);
 			} else {
@@ -229,7 +249,16 @@ start:
 			} else if (length_mod == 'l') {
 				x = va_arg(ap, unsigned long);
 			} else if (length_mod == 'L') {
-				x = va_arg(ap, unsigned long long);
+				unsigned long long llx =
+					va_arg(ap, unsigned long long);
+
+				if (llx != (uint_value_type) llx) {
+					data = "ERR";
+					data_len = 3;
+					precision = 0;
+					break;
+				}
+				x = (uint_value_type) llx;
 			} else {
 				x = va_arg(ap, unsigned int);
 			}
diff --git a/tests/kernel/common/src/printk.c b/tests/kernel/common/src/printk.c
index a29ca9e0468..4e60686078c 100644
--- a/tests/kernel/common/src/printk.c
+++ b/tests/kernel/common/src/printk.c
@@ -51,7 +51,7 @@ char *expected = "22 113 10000 32768 40000 22\n"
 		 "42 42   42       42\n"
 		 "42 42 0042 00000042\n"
 		 "255     42    abcdef        42\n"
-		 "ERR -1 4294967295 ffffffff\n"
+		 "ERR -1 ERR ERR\n"
 		 "0xcafebabe 0xbeef 0x2a\n"
 ;
 #endif
diff --git a/tests/unit/cbprintf/main.c b/tests/unit/cbprintf/main.c
index 19e23f8af9f..b4c40d7f820 100644
--- a/tests/unit/cbprintf/main.c
+++ b/tests/unit/cbprintf/main.c
@@ -510,6 +510,7 @@ static void test_d_length(void)
 	int max = 1876543210;
 	long long svll = 123LL << 48;
 	long long svll2 = -2LL;
+	unsigned long long uvll = 4000000000LLU;
 	int rc;
 
 	TEST_PRF(&rc, "%d/%d", min, max);
@@ -526,22 +527,22 @@ static void test_d_length(void)
 		PRF_CHECK("46/-22", rc);
 	}
 
-	TEST_PRF(&rc, "%ld/%ld", (long)min, (long)max);
+	TEST_PRF(&rc, "%ld/%ld/%lu/", (long)min, (long)max, 4000000000UL);
 	if (IS_ENABLED(CONFIG_CBPRINTF_FULL_INTEGRAL)
 	    || (sizeof(long) <= 4)
 	    || IS_ENABLED(CONFIG_CBPRINTF_NANO)) {
-		PRF_CHECK("-1234567890/1876543210", rc);
+		PRF_CHECK("-1234567890/1876543210/4000000000/", rc);
 	} else {
-		PRF_CHECK("%ld/%ld", rc);
+		PRF_CHECK("%ld/%ld/%lu/", rc);
 	}
 
-	TEST_PRF(&rc, "/%lld/%lld/%lld/", svll, -svll, svll2);
+	TEST_PRF(&rc, "/%lld/%lld/%lld/%llu/", svll, -svll, svll2, uvll);
 	if (IS_ENABLED(CONFIG_CBPRINTF_FULL_INTEGRAL)) {
-		PRF_CHECK("/34621422135410688/-34621422135410688/-2/", rc);
+		PRF_CHECK("/34621422135410688/-34621422135410688/-2/4000000000/", rc);
 	} else if (IS_ENABLED(CONFIG_CBPRINTF_COMPLETE)) {
-		PRF_CHECK("/%lld/%lld/%lld/", rc);
+		PRF_CHECK("/%lld/%lld/%lld/%llu/", rc);
 	} else if (IS_ENABLED(CONFIG_CBPRINTF_NANO)) {
-		PRF_CHECK("/ERR/ERR/-2/", rc);
+		PRF_CHECK("/ERR/ERR/-2/4000000000/", rc);
 	} else {
 		zassert_true(false, "Missed case!");
 	}