diff --git a/chunihook/jvs.c b/chunihook/jvs.c
index a57c2a3..8c630d4 100644
--- a/chunihook/jvs.c
+++ b/chunihook/jvs.c
@@ -31,7 +31,8 @@ static const struct io3_ops chunithm_jvs_io3_ops = {
     .read_coin_counter  = chunithm_jvs_read_coin_counter,
 };
 
-static const struct chunithm_jvs_ir_mask chunithm_jvs_ir_masks[] = {
+// Incorrect IR beam mappings retained for backward compatibility
+static const struct chunithm_jvs_ir_mask chunithm_jvs_ir_masks_v1[] = {
     { 0x0000, 0x0020 },
     { 0x0020, 0x0000 },
     { 0x0000, 0x0010 },
@@ -40,6 +41,15 @@ static const struct chunithm_jvs_ir_mask chunithm_jvs_ir_masks[] = {
     { 0x0008, 0x0000 },
 };
 
+static const struct chunithm_jvs_ir_mask chunithm_jvs_ir_masks[] = {
+    { 0x0020, 0x0000 },
+    { 0x0000, 0x0020 },
+    { 0x0010, 0x0000 },
+    { 0x0000, 0x0010 },
+    { 0x0008, 0x0000 },
+    { 0x0000, 0x0008 },
+};
+
 static struct io3 chunithm_jvs_io3;
 
 HRESULT chunithm_jvs_init(struct jvs_node **out)
@@ -66,6 +76,7 @@ HRESULT chunithm_jvs_init(struct jvs_node **out)
 
 static void chunithm_jvs_read_switches(void *ctx, struct io3_switch_state *out)
 {
+    const struct chunithm_jvs_ir_mask *masks;
     uint8_t opbtn;
     uint8_t beams;
     size_t i;
@@ -73,6 +84,14 @@ static void chunithm_jvs_read_switches(void *ctx, struct io3_switch_state *out)
     assert(out != NULL);
     assert(chuni_dll.jvs_poll != NULL);
 
+    if (chuni_dll.api_version >= 0x0101) {
+        // Use correct mapping
+        masks = chunithm_jvs_ir_masks;
+    } else {
+        // Use backwards-compatible incorrect mapping
+        masks = chunithm_jvs_ir_masks_v1;
+    }
+
     opbtn = 0;
     beams = 0;
 
@@ -95,8 +114,8 @@ static void chunithm_jvs_read_switches(void *ctx, struct io3_switch_state *out)
     for (i = 0 ; i < 6 ; i++) {
         /* Beam "press" is active-low hence the ~ */
         if (~beams & (1 << i)) {
-            out->p1 |= chunithm_jvs_ir_masks[i].p1;
-            out->p2 |= chunithm_jvs_ir_masks[i].p2;
+            out->p1 |= masks[i].p1;
+            out->p2 |= masks[i].p2;
         }
     }
 }
diff --git a/chuniio/chuniio.c b/chuniio/chuniio.c
index 91971f3..8813e68 100644
--- a/chuniio/chuniio.c
+++ b/chuniio/chuniio.c
@@ -18,7 +18,7 @@ static struct chuni_io_config chuni_io_cfg;
 
 uint16_t chuni_io_get_api_version(void)
 {
-    return 0x0100;
+    return 0x0101;
 }
 
 HRESULT chuni_io_jvs_init(void)
diff --git a/chuniio/chuniio.h b/chuniio/chuniio.h
index 8d0bc1c..87e7e76 100644
--- a/chuniio/chuniio.h
+++ b/chuniio/chuniio.h
@@ -1,5 +1,15 @@
 #pragma once
 
+/*
+   CHUNITHM CUSTOM IO API
+
+   Changelog:
+
+   - 0x0100: Initial API version (assumed if chuni_io_get_api_version is not
+     exported)
+   - 0x0101: Fix IR beam mappings
+*/
+
 #include <windows.h>
 
 #include <stdbool.h>
@@ -10,7 +20,7 @@
    the major version and the low byte is the minor version (as defined by the
    Semantic Versioning standard).
 
-   The latest API version as of this writing is 0x0100. */
+   The latest API version as of this writing is 0x0101. */
 
 uint16_t chuni_io_get_api_version(void);
 
@@ -41,7 +51,12 @@ HRESULT chuni_io_jvs_init(void);
    a gradual raising and lowering of the hands. Consult the proof-of-concept
    implementation for details.
 
-   Minimum API version: 0x0100 */
+   NOTE: Previous releases of Segatools mapped the IR beam inputs incorrectly.
+   Please ensure that you advertise an API version of at least 0x0101 so that
+   the correct mapping can be used.
+
+   Minimum API version: 0x0100
+   Latest API version: 0x0101 */
 
 void chuni_io_jvs_poll(uint8_t *opbtn, uint8_t *beams);