diff --git a/libloragw/src/loragw_fpga.c b/libloragw/src/loragw_fpga.c
index fa83a2a..7e667e3 100644
--- a/libloragw/src/loragw_fpga.c
+++ b/libloragw/src/loragw_fpga.c
@@ -144,11 +144,14 @@ int lgw_fpga_configure(uint32_t tx_notch_freq) {
         return LGW_REG_ERROR;
     }
 
-    /* Required for Semtech AP2 reference design */
-    x  = lgw_fpga_reg_w(LGW_FPGA_CTRL_INVERT_IQ, 1);
-    if (x != LGW_REG_SUCCESS) {
-        DEBUG_MSG("ERROR: Failed to configure FPGA polarity\n");
-        return LGW_REG_ERROR;
+
+    if (read_fpga_version() > 28) {
+        /* Required for Semtech AP2 reference design and AP1.5 > v28 */
+        x  = lgw_fpga_reg_w(LGW_FPGA_CTRL_INVERT_IQ, 1);
+        if (x != LGW_REG_SUCCESS) {
+            DEBUG_MSG("ERROR: Failed to configure FPGA polarity\n");
+            return LGW_REG_ERROR;
+        }
     }
 
     /* Configure TX notch filter */