diff --git a/src/main/java/org/apache/commons/lang3/StringUtils.java b/src/main/java/org/apache/commons/lang3/StringUtils.java
index d7999e7f9..bb8136555 100644
--- a/src/main/java/org/apache/commons/lang3/StringUtils.java
+++ b/src/main/java/org/apache/commons/lang3/StringUtils.java
@@ -6151,7 +6151,10 @@ public class StringUtils {
      * StringUtils.isAllLowerCase("")     = false
      * StringUtils.isAllLowerCase("  ")   = false
      * StringUtils.isAllLowerCase("abc")  = true
-     * StringUtils.isAllLowerCase("abC") = false
+     * StringUtils.isAllLowerCase("abC")  = false
+     * StringUtils.isAllLowerCase("ab c") = false
+     * StringUtils.isAllLowerCase("ab1c") = false
+     * StringUtils.isAllLowerCase("ab/c") = false
      * </pre>
      *
      * @param cs  the CharSequence to check, may be null
@@ -6183,7 +6186,10 @@ public class StringUtils {
      * StringUtils.isAllUpperCase("")     = false
      * StringUtils.isAllUpperCase("  ")   = false
      * StringUtils.isAllUpperCase("ABC")  = true
-     * StringUtils.isAllUpperCase("aBC") = false
+     * StringUtils.isAllUpperCase("aBC")  = false
+     * StringUtils.isAllUpperCase("A C")  = false
+     * StringUtils.isAllUpperCase("A1C")  = false
+     * StringUtils.isAllUpperCase("A/C")  = false
      * </pre>
      *
      * @param cs the CharSequence to check, may be null
diff --git a/src/test/java/org/apache/commons/lang3/StringUtilsTest.java b/src/test/java/org/apache/commons/lang3/StringUtilsTest.java
index e9931ffc4..5654589de 100644
--- a/src/test/java/org/apache/commons/lang3/StringUtilsTest.java
+++ b/src/test/java/org/apache/commons/lang3/StringUtilsTest.java
@@ -2066,9 +2066,14 @@ public class StringUtilsTest {
     public void testIsAllLowerCase() {
         assertFalse(StringUtils.isAllLowerCase(null));
         assertFalse(StringUtils.isAllLowerCase(StringUtils.EMPTY));
+        assertFalse(StringUtils.isAllLowerCase("  "));
         assertTrue(StringUtils.isAllLowerCase("abc"));
         assertFalse(StringUtils.isAllLowerCase("abc "));
+        assertFalse(StringUtils.isAllLowerCase("abc\n"));
         assertFalse(StringUtils.isAllLowerCase("abC"));
+        assertFalse(StringUtils.isAllLowerCase("ab c"));
+        assertFalse(StringUtils.isAllLowerCase("ab1c"));
+        assertFalse(StringUtils.isAllLowerCase("ab/c"));
     }
 
     /**
@@ -2078,9 +2083,14 @@ public class StringUtilsTest {
     public void testIsAllUpperCase() {
         assertFalse(StringUtils.isAllUpperCase(null));
         assertFalse(StringUtils.isAllUpperCase(StringUtils.EMPTY));
+        assertFalse(StringUtils.isAllUpperCase("  "));
         assertTrue(StringUtils.isAllUpperCase("ABC"));
         assertFalse(StringUtils.isAllUpperCase("ABC "));
+        assertFalse(StringUtils.isAllUpperCase("ABC\n"));
         assertFalse(StringUtils.isAllUpperCase("aBC"));
+        assertFalse(StringUtils.isAllUpperCase("A C"));
+        assertFalse(StringUtils.isAllUpperCase("A1C"));
+        assertFalse(StringUtils.isAllUpperCase("A/C"));
     }
 
     @Test