diff --git a/vlib/compiler/scanner.v b/vlib/compiler/scanner.v
index 073771d912..3c37340fdc 100644
--- a/vlib/compiler/scanner.v
+++ b/vlib/compiler/scanner.v
@@ -147,6 +147,9 @@ fn (s mut Scanner) ident_bin_number() string {
 		}
 		s.pos++
 	}
+	if start_pos + 2 == s.pos {
+		s.error('number part of this binary is not provided')
+	}
 	number := filter_num_sep(s.text.str, start_pos, s.pos)
 	s.pos--
 	return number
@@ -165,6 +168,9 @@ fn (s mut Scanner) ident_hex_number() string {
 		}
 		s.pos++
 	}
+	if start_pos + 2 == s.pos {
+		s.error('number part of this hexadecimal is not provided')
+	}
 	number := filter_num_sep(s.text.str, start_pos, s.pos)
 	s.pos--
 	return number
@@ -183,6 +189,9 @@ fn (s mut Scanner) ident_oct_number() string {
 		}
 		s.pos++
 	}
+	if start_pos + 2 == s.pos {
+		s.error('number part of this octal is not provided')
+	}
 	number := filter_num_sep(s.text.str, start_pos, s.pos)
 	s.pos--
 	return number
diff --git a/vlib/v/scanner/scanner.v b/vlib/v/scanner/scanner.v
index ac978eaf93..8196eec339 100644
--- a/vlib/v/scanner/scanner.v
+++ b/vlib/v/scanner/scanner.v
@@ -143,6 +143,9 @@ fn (s mut Scanner) ident_bin_number() string {
 		}
 		s.pos++
 	}
+	if start_pos + 2 == s.pos {
+		s.error('number part of this binary is not provided')
+	}
 	number := filter_num_sep(s.text.str, start_pos, s.pos)
 	s.pos--
 	return number
@@ -161,6 +164,9 @@ fn (s mut Scanner) ident_hex_number() string {
 		}
 		s.pos++
 	}
+	if start_pos + 2 == s.pos {
+		s.error('number part of this hexadecimal is not provided')
+	}
 	number := filter_num_sep(s.text.str, start_pos, s.pos)
 	s.pos--
 	return number
@@ -179,6 +185,9 @@ fn (s mut Scanner) ident_oct_number() string {
 		}
 		s.pos++
 	}
+	if start_pos + 2 == s.pos {
+		s.error('number part of this octal is not provided')
+	}
 	number := filter_num_sep(s.text.str, start_pos, s.pos)
 	s.pos--
 	return number