diff --git a/core/src/main/java/org/testcontainers/utility/TestcontainersConfiguration.java b/core/src/main/java/org/testcontainers/utility/TestcontainersConfiguration.java
index 18cfdaff303..e52a8be7297 100644
--- a/core/src/main/java/org/testcontainers/utility/TestcontainersConfiguration.java
+++ b/core/src/main/java/org/testcontainers/utility/TestcontainersConfiguration.java
@@ -12,6 +12,7 @@
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang.exception.ExceptionUtils;
 import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.testcontainers.UnstableAPI;
 
@@ -186,7 +187,7 @@ public Integer getImagePullPauseTimeout() {
      */
     @Nullable
     @Contract("_, !null -> !null")
-    public String getEnvVarOrProperty(final String propertyName, @Nullable final String defaultValue) {
+    public String getEnvVarOrProperty(@NotNull final String propertyName, @Nullable final String defaultValue) {
         String envVarName = propertyName.replaceAll("\\.", "_").toUpperCase();
         if (!propertyName.startsWith("TESTCONTAINERS_")) {
             envVarName = "TESTCONTAINERS_" + envVarName;
diff --git a/core/src/test/java/org/testcontainers/utility/PrefixingImageNameSubstitutorTest.java b/core/src/test/java/org/testcontainers/utility/PrefixingImageNameSubstitutorTest.java
index 0b0328b1890..3e6675660cf 100644
--- a/core/src/test/java/org/testcontainers/utility/PrefixingImageNameSubstitutorTest.java
+++ b/core/src/test/java/org/testcontainers/utility/PrefixingImageNameSubstitutorTest.java
@@ -3,6 +3,7 @@
 import org.junit.Before;
 import org.junit.Test;
 
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
@@ -22,7 +23,7 @@ public void setUp() {
 
     @Test
     public void testHappyPath() {
-        when(mockConfiguration.getEnvVarOrProperty(eq(PROPERTY_KEY))).thenReturn("someregistry.com/");
+        when(mockConfiguration.getEnvVarOrProperty(eq(PROPERTY_KEY), any())).thenReturn("someregistry.com/");
 
         final DockerImageName result = underTest.apply(DockerImageName.parse("some/image:tag"));
 
@@ -35,7 +36,7 @@ public void testHappyPath() {
 
     @Test
     public void testNoDoublePrefixing() {
-        when(mockConfiguration.getEnvVarOrProperty(eq(PROPERTY_KEY))).thenReturn("someregistry.com/");
+        when(mockConfiguration.getEnvVarOrProperty(eq(PROPERTY_KEY), any())).thenReturn("someregistry.com/");
 
         final DockerImageName result = underTest.apply(DockerImageName.parse("someregistry.com/some/image:tag"));
 
@@ -48,7 +49,7 @@ public void testNoDoublePrefixing() {
 
     @Test
     public void testHandlesNullValue() {
-        when(mockConfiguration.getEnvVarOrProperty(eq(PROPERTY_KEY))).thenReturn(null);
+        when(mockConfiguration.getEnvVarOrProperty(eq(PROPERTY_KEY), any())).thenReturn(null);
 
         final DockerImageName result = underTest.apply(DockerImageName.parse("some/image:tag"));
 
@@ -61,7 +62,7 @@ public void testHandlesNullValue() {
 
     @Test
     public void testHandlesEmptyValue() {
-        when(mockConfiguration.getEnvVarOrProperty(eq(PROPERTY_KEY))).thenReturn("");
+        when(mockConfiguration.getEnvVarOrProperty(eq(PROPERTY_KEY), any())).thenReturn("");
 
         final DockerImageName result = underTest.apply(DockerImageName.parse("some/image:tag"));