diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ec4fbce2..19f1356c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,7 +17,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ ubuntu-latest, windows-latest, macos-latest ]
-        java: [ 8, 11, 17, 18 ]
+        java: [ 8, 11, 17, 20 ]
     runs-on: ${{ matrix.os }}
     permissions:
       checks: write
diff --git a/common/common-lang/src/main/java/com/twelvemonkeys/lang/StringUtil.java b/common/common-lang/src/main/java/com/twelvemonkeys/lang/StringUtil.java
index d1f88c93..3a6b1bf0 100755
--- a/common/common-lang/src/main/java/com/twelvemonkeys/lang/StringUtil.java
+++ b/common/common-lang/src/main/java/com/twelvemonkeys/lang/StringUtil.java
@@ -904,7 +904,7 @@ public final class StringUtil {
         }
         catch (ParseException pe) {
             // Wrap in RuntimeException
-            throw new IllegalArgumentException(pe.getMessage());
+            throw new IllegalArgumentException(pe.getMessage() + " at pos " + pe.getErrorOffset());
         }
     }
 
diff --git a/common/common-lang/src/test/java/com/twelvemonkeys/lang/StringUtilTest.java b/common/common-lang/src/test/java/com/twelvemonkeys/lang/StringUtilTest.java
index 923cffd0..c6863961 100644
--- a/common/common-lang/src/test/java/com/twelvemonkeys/lang/StringUtilTest.java
+++ b/common/common-lang/src/test/java/com/twelvemonkeys/lang/StringUtilTest.java
@@ -593,8 +593,8 @@ public class StringUtilTest {
         cal.clear();
         cal.set(Calendar.HOUR, 1);
         cal.set(Calendar.MINUTE, 2);
-        date = StringUtil.toDate("1:02 am",
-                                 DateFormat.getTimeInstance(DateFormat.SHORT, Locale.US));
+        format = new SimpleDateFormat("HH:mm");
+        date = StringUtil.toDate("1:02", format);
         assertNotNull(date);
         assertEquals(cal.getTime(), date);
     }
diff --git a/imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/color/KCMSSanitizerStrategyTest.java b/imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/color/KCMSSanitizerStrategyTest.java
index 3cf80a29..c8b8ae61 100644
--- a/imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/color/KCMSSanitizerStrategyTest.java
+++ b/imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/color/KCMSSanitizerStrategyTest.java
@@ -36,9 +36,11 @@ import java.awt.color.ColorSpace;
 import java.awt.color.ICC_ColorSpace;
 import java.awt.color.ICC_Profile;
 import java.io.IOException;
+import java.lang.reflect.Method;
 import java.util.Arrays;
 
 import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assume.assumeFalse;
 import static org.mockito.Mockito.*;
 
 public class KCMSSanitizerStrategyTest {
@@ -56,6 +58,8 @@ public class KCMSSanitizerStrategyTest {
 
     @Test
     public void testFixProfileUpdateHeader() throws Exception {
+        assumeICC_ProfileNotSealed(); // Ignores test for JDK 19+
+
         byte[] header = new byte[128];
         header[ICC_Profile.icHdrRenderingIntent + 3] = 1;
         ICC_Profile profile = mock(ICC_Profile.class);
@@ -69,6 +73,17 @@ public class KCMSSanitizerStrategyTest {
         verify(profile).setData(eq(ICC_Profile.icSigHead), any(byte[].class));
     }
 
+    static void assumeICC_ProfileNotSealed() {
+        try {
+            Method isSealed = Class.class.getMethod("isSealed");
+            Boolean result = (Boolean) isSealed.invoke(ICC_Profile.class);
+            assumeFalse("Can't mock ICC_Profile, class is sealed (as of JDK 19).", result);
+        }
+        catch (ReflectiveOperationException ignore) {
+            // We can't have sealed classes if we don't have the isSealed method...
+        }
+    }
+
     @Test
     public void testFixProfileCorbisRGB() throws IOException {
         // TODO: Consider re-writing this using mocks, to avoid dependencies on the CMS implementation
diff --git a/imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/color/LCMSSanitizerStrategyTest.java b/imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/color/LCMSSanitizerStrategyTest.java
index d7b63ea2..cff1acbd 100644
--- a/imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/color/LCMSSanitizerStrategyTest.java
+++ b/imageio/imageio-core/src/test/java/com/twelvemonkeys/imageio/color/LCMSSanitizerStrategyTest.java
@@ -34,6 +34,7 @@ import org.junit.Test;
 
 import java.awt.color.ICC_Profile;
 
+import static com.twelvemonkeys.imageio.color.KCMSSanitizerStrategyTest.assumeICC_ProfileNotSealed;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 
@@ -46,6 +47,8 @@ public class LCMSSanitizerStrategyTest {
 
     @Test
     public void testFixProfile() throws Exception {
+        assumeICC_ProfileNotSealed(); // Ignores test for JDK 19+
+
         ICC_Profile profile = mock(ICC_Profile.class);
         new LCMSSanitizerStrategy().fixProfile(profile);
 
diff --git a/pom.xml b/pom.xml
index 7869e718..f7d51e1e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -224,8 +224,8 @@
                     <version>3.11.0</version>
                     <inherited>true</inherited>
                     <configuration>
-                        <source>1.7</source>
-                        <target>1.7</target>
+                        <source>8</source>
+                        <target>8</target>
                         <showDeprecation>false</showDeprecation>
                         <debuglevel>source,lines</debuglevel>
                         <compilerArguments>