diff --git a/src/main/java/org/openjdk/jextract/JextractTool.java b/src/main/java/org/openjdk/jextract/JextractTool.java
index 4f3c92a0..7193b6bf 100644
--- a/src/main/java/org/openjdk/jextract/JextractTool.java
+++ b/src/main/java/org/openjdk/jextract/JextractTool.java
@@ -484,6 +484,11 @@ private int run(String[] args) {
 
         builder.addClangArg("-I" + System.getProperty("user.dir"));
 
+        // 64 bit mode on AIX
+        if (System.getProperty("os.name").toLowerCase().contains("aix")) {
+            builder.addClangArg("-m64");
+        }
+
         if (optionSet.nonOptionArguments().isEmpty()) {
             printOptionError(logger.format("expected.atleast.one.header"));
             return OPTION_ERROR;
diff --git a/src/main/java/org/openjdk/jextract/impl/TypeImpl.java b/src/main/java/org/openjdk/jextract/impl/TypeImpl.java
index 24184f57..cdef2245 100644
--- a/src/main/java/org/openjdk/jextract/impl/TypeImpl.java
+++ b/src/main/java/org/openjdk/jextract/impl/TypeImpl.java
@@ -43,6 +43,7 @@
 public abstract class TypeImpl implements Type {
 
     public static final boolean IS_WINDOWS = System.getProperty("os.name").startsWith("Windows");
+    public static final boolean IS_AIX = System.getProperty("os.name").startsWith("AIX");
 
     @Override
     public boolean isErroneous() {
diff --git a/test/jtreg/generator/testStruct/LibStructTest.java b/test/jtreg/generator/testStruct/LibStructTest.java
index 4851f22c..e2f2a776 100644
--- a/test/jtreg/generator/testStruct/LibStructTest.java
+++ b/test/jtreg/generator/testStruct/LibStructTest.java
@@ -42,6 +42,9 @@
  * @run testng/othervm --enable-native-access=ALL-UNNAMED LibStructTest
  */
 public class LibStructTest {
+
+    public static final boolean IS_AIX = System.getProperty("os.name").startsWith("AIX");
+
     @Test
     public void testMakePoint() {
         try (Arena arena = Arena.ofConfined()) {
@@ -97,6 +100,10 @@ public void testFieldTypes() {
         checkField(g, "ll", C_LONG_LONG);
         checkField(g, "ull",C_LONG_LONG);
         checkField(g, "f",  C_FLOAT);
-        checkField(g, "d",  C_DOUBLE);
+        if (IS_AIX) {
+            checkField(g, "d",  C_DOUBLE.withByteAlignment(4));
+        } else {
+            checkField(g, "d", C_DOUBLE);
+        }
     }
 }
diff --git a/test/lib/testlib/JextractToolRunner.java b/test/lib/testlib/JextractToolRunner.java
index d6dc9336..170f577e 100644
--- a/test/lib/testlib/JextractToolRunner.java
+++ b/test/lib/testlib/JextractToolRunner.java
@@ -56,6 +56,7 @@ public class JextractToolRunner {
     public static final boolean IS_WINDOWS = System.getProperty("os.name").startsWith("Windows");
     public static final boolean IS_LINUX = System.getProperty("os.name").equals("Linux");
     public static final boolean IS_AARCH64 = System.getProperty("os.arch").equals("aarch64");
+    public static final boolean IS_AIX = System.getProperty("os.name").equals("AIX");
 
     public static final ValueLayout.OfBoolean C_BOOL = ValueLayout.JAVA_BOOLEAN;
     public static final ValueLayout.OfByte C_CHAR = ValueLayout.JAVA_BYTE;
diff --git a/test/testng/org/openjdk/jextract/test/toolprovider/nestedAnonOffset/TestNestedAnonOffset.java b/test/testng/org/openjdk/jextract/test/toolprovider/nestedAnonOffset/TestNestedAnonOffset.java
index 2fe582cf..e9ff5110 100644
--- a/test/testng/org/openjdk/jextract/test/toolprovider/nestedAnonOffset/TestNestedAnonOffset.java
+++ b/test/testng/org/openjdk/jextract/test/toolprovider/nestedAnonOffset/TestNestedAnonOffset.java
@@ -91,7 +91,7 @@ public void testBaz() {
         StructLayout layout = (StructLayout) findLayout(baz);
         assertEquals(layout.memberLayouts().get(0), C_CHAR.withName("c"));
         // Note here: on some platforms, the bitfield needs to be aligned and requires more padding
-        int paddingBytes = (IS_WINDOWS || (IS_LINUX && IS_AARCH64)) ? 11 : 8;
+        int paddingBytes = (IS_WINDOWS || (IS_LINUX && IS_AARCH64) || IS_AIX) ? 11 : 8;
         assertEquals(layout.memberLayouts().get(1), MemoryLayout.paddingLayout(paddingBytes));
     }