diff --git a/libavfilter/dnn/dnn_backend_native_layer_mathunary.c b/libavfilter/dnn/dnn_backend_native_layer_mathunary.c
index a62f6ba6f0..f9f88983f9 100644
--- a/libavfilter/dnn/dnn_backend_native_layer_mathunary.c
+++ b/libavfilter/dnn/dnn_backend_native_layer_mathunary.c
@@ -134,6 +134,10 @@ int dnn_execute_layer_math_unary(DnnOperand *operands, const int32_t *input_oper
         for (int i = 0; i < dims_count; ++i)
             dst[i] = ceil(src[i]);
         return 0;
+    case DMUO_FLOOR:
+        for (int i = 0; i < dims_count; ++i)
+            dst[i] = floor(src[i]);
+        return 0;
     default:
         return -1;
     }
diff --git a/libavfilter/dnn/dnn_backend_native_layer_mathunary.h b/libavfilter/dnn/dnn_backend_native_layer_mathunary.h
index 82b2d7f4ab..1b78fbe1c2 100644
--- a/libavfilter/dnn/dnn_backend_native_layer_mathunary.h
+++ b/libavfilter/dnn/dnn_backend_native_layer_mathunary.h
@@ -44,6 +44,7 @@ typedef enum {
     DMUO_ACOSH = 11,
     DMUO_ATANH = 12,
     DMUO_CEIL = 13,
+    DMUO_FLOOR = 14,
     DMUO_COUNT
 } DNNMathUnaryOperation;
 
diff --git a/tests/dnn/dnn-layer-mathunary-test.c b/tests/dnn/dnn-layer-mathunary-test.c
index 7da3a206ed..0bfcdcbd85 100644
--- a/tests/dnn/dnn-layer-mathunary-test.c
+++ b/tests/dnn/dnn-layer-mathunary-test.c
@@ -58,6 +58,8 @@ static float get_expected(float f, DNNMathUnaryOperation op)
         return atanh(f);
     case DMUO_CEIL:
         return ceil(f);
+    case DMUO_FLOOR:
+        return floor(f);
     default:
         av_assert0(!"not supported yet");
         return 0.f;
@@ -132,5 +134,7 @@ int main(int agrc, char **argv)
         return 1;
     if (test(DMUO_CEIL))
         return 1;
+    if (test(DMUO_FLOOR))
+        return 1;
     return 0;
 }
diff --git a/tools/python/convert_from_tensorflow.py b/tools/python/convert_from_tensorflow.py
index 64b7551314..2fb8c4c303 100644
--- a/tools/python/convert_from_tensorflow.py
+++ b/tools/python/convert_from_tensorflow.py
@@ -74,7 +74,7 @@ class TFConverter:
         self.mathbin2code = {'Sub':0, 'Add':1, 'Mul':2, 'RealDiv':3, 'Minimum':4}
         self.mathun2code  = {'Abs':0, 'Sin':1, 'Cos':2, 'Tan':3, 'Asin':4,
                 'Acos':5, 'Atan':6, 'Sinh':7, 'Cosh':8, 'Tanh':9, 'Asinh':10,
-                'Acosh':11, 'Atanh':12, 'Ceil':13}
+                'Acosh':11, 'Atanh':12, 'Ceil':13, 'Floor':14}
         self.mirrorpad_mode = {'CONSTANT':0, 'REFLECT':1, 'SYMMETRIC':2}
         self.name_operand_dict = {}
 
diff --git a/tools/python/convert_header.py b/tools/python/convert_header.py
index 62f1d342f3..b12b5079fc 100644
--- a/tools/python/convert_header.py
+++ b/tools/python/convert_header.py
@@ -23,4 +23,4 @@ str = 'FFMPEGDNNNATIVE'
 major = 1
 
 # increase minor when we don't have to re-convert the model file
-minor = 19
+minor = 20