diff --git a/gwt-safecss/src/main/java/org/gwtproject/safecss/shared/SafeStylesHostedModeUtils.java b/gwt-safecss/src/main/java/org/gwtproject/safecss/shared/SafeStylesHostedModeUtils.java
index 98e0c06..9ebbfa7 100644
--- a/gwt-safecss/src/main/java/org/gwtproject/safecss/shared/SafeStylesHostedModeUtils.java
+++ b/gwt-safecss/src/main/java/org/gwtproject/safecss/shared/SafeStylesHostedModeUtils.java
@@ -31,6 +31,10 @@ public class SafeStylesHostedModeUtils {
 
   private static boolean forceCheck;
 
+  static {
+    setForceCheckValidStyleFromProperty();
+  }
+
   /**
    * Checks if the provided string is a valid style property name.
    *
diff --git a/gwt-safecss/src/main/module.gwt.xml b/gwt-safecss/src/main/module.gwt.xml
index 8db9000..1276f72 100644
--- a/gwt-safecss/src/main/module.gwt.xml
+++ b/gwt-safecss/src/main/module.gwt.xml
@@ -22,6 +22,6 @@
   <inherits name="org.gwtproject.safehtml.SafeHtml"/>
 
   <define-configuration-property name="org.gwtproject.safecss.ForceCheckValidStyles" is-multi-valued="false"/>
-
+  <set-configuration-property name="org.gwtproject.safecss.ForceCheckValidStyles" value="false"/>
   <source path="shared"/>
 </module>
diff --git a/gwt-safehtml/src/main/java/org/gwtproject/safehtml/shared/SafeHtmlHostedModeUtils.java b/gwt-safehtml/src/main/java/org/gwtproject/safehtml/shared/SafeHtmlHostedModeUtils.java
index 170dbd8..55326f3 100644
--- a/gwt-safehtml/src/main/java/org/gwtproject/safehtml/shared/SafeHtmlHostedModeUtils.java
+++ b/gwt-safehtml/src/main/java/org/gwtproject/safehtml/shared/SafeHtmlHostedModeUtils.java
@@ -174,7 +174,7 @@ private static void checkArgument(boolean completeHtml, String message) {
     @GwtIncompatible
     @Override
     public boolean getForceCheckCompleteHtmlFromProperty() {
-      return System.getProperty(FORCE_CHECK_COMPLETE_HTML) != null;
+      return "true".equals(System.getProperty(FORCE_CHECK_COMPLETE_HTML));
     }
   }
 }
diff --git a/gwt-safehtml/src/main/java/org/gwtproject/safehtml/shared/SafeUriHostedModeUtils.java b/gwt-safehtml/src/main/java/org/gwtproject/safehtml/shared/SafeUriHostedModeUtils.java
index 5a0ae60..dbdcef6 100644
--- a/gwt-safehtml/src/main/java/org/gwtproject/safehtml/shared/SafeUriHostedModeUtils.java
+++ b/gwt-safehtml/src/main/java/org/gwtproject/safehtml/shared/SafeUriHostedModeUtils.java
@@ -134,7 +134,7 @@ public static void setForceCheckValidUri(boolean check) {
   //
   // @VisibleForTesting
   public static void setForceCheckValidUriFromProperty() {
-    forceCheckValidUri = impl.getForceCheckValieUriFromProperty();
+    forceCheckValidUri = impl.getForceCheckValidUriFromProperty();
   }
 
   private static class JsImpl {
@@ -143,7 +143,7 @@ public boolean isValidUri(String uri) {
       return true;
     }
 
-    public boolean getForceCheckValieUriFromProperty() {
+    public boolean getForceCheckValidUriFromProperty() {
       return false;
     }
   }
@@ -169,8 +169,8 @@ public boolean isValidUri(String uri) {
 
     @GwtIncompatible
     @Override
-    public boolean getForceCheckValieUriFromProperty() {
-      return System.getProperty(FORCE_CHECK_VALID_URI) != null;
+    public boolean getForceCheckValidUriFromProperty() {
+      return "true".equals(System.getProperty(FORCE_CHECK_VALID_URI));
     }
   }
 }
diff --git a/gwt-safehtml/src/main/module.gwt.xml b/gwt-safehtml/src/main/module.gwt.xml
index 63e828f..03aed4e 100644
--- a/gwt-safehtml/src/main/module.gwt.xml
+++ b/gwt-safehtml/src/main/module.gwt.xml
@@ -22,4 +22,9 @@
   <!-- sources -->
   <source path="client"/>
   <source path="shared"/>
+
+  <define-configuration-property name="com.google.gwt.safehtml.ForceCheckCompleteHtml" is-multi-valued="false"/>
+  <set-configuration-property name="com.google.gwt.safehtml.ForceCheckCompleteHtml" value="false"/>
+  <define-configuration-property name="com.google.gwt.safehtml.ForceCheckValidUri" is-multi-valued="false"/>
+  <set-configuration-property name="com.google.gwt.safehtml.ForceCheckValidUri" value="false"/>
 </module>
\ No newline at end of file