diff --git a/apex/apex_test.go b/apex/apex_test.go
index 07372a3..7905710 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -6227,6 +6227,9 @@
 			name: "mybootclasspath_fragment",
 			contents: ["bcplib"],
 			apex_available: ["myapex"],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		java_library {
@@ -6241,6 +6244,9 @@
 			name: "override_bootclasspath_fragment",
 			contents: ["override_bcplib"],
 			apex_available: ["myapex"],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		java_library {
@@ -7294,6 +7300,9 @@
 			apex_available: [
 				"some-non-updatable-apex",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		java_library {
@@ -7352,6 +7361,9 @@
 			apex_available: [
 				"com.android.art.debug",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		apex_key {
@@ -8695,6 +8707,9 @@
 			name: "mybootclasspathfragment",
 			contents: ["mybootclasspathlib"],
 			apex_available: ["myapex"],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		java_library {
@@ -9015,6 +9030,9 @@
 				name: "mybootclasspathfragment",
 				contents: ["mybootclasspathlib"],
 				apex_available: ["myapex"],
+				hidden_api: {
+					split_packages: ["*"],
+				},
 			}
 
 			java_sdk_library {
@@ -9115,6 +9133,9 @@
 					name: "mybootclasspathfragment",
 					contents: ["mybootclasspathlib"],
 					apex_available: ["myapex"],
+					hidden_api: {
+						split_packages: ["*"],
+					},
 				}
 
 				java_sdk_library {
@@ -9334,6 +9355,9 @@
 			name: "mybootclasspathfragment",
 			contents: ["myjavalib"],
 			apex_available: ["myapex"],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 		java_library {
 			name: "myjavalib",
diff --git a/apex/bootclasspath_fragment_test.go b/apex/bootclasspath_fragment_test.go
index ce6b7f7..b298dac 100644
--- a/apex/bootclasspath_fragment_test.go
+++ b/apex/bootclasspath_fragment_test.go
@@ -110,6 +110,9 @@
 			apex_available: [
 				"com.android.art",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 `,
 	)
@@ -209,6 +212,9 @@
 			apex_available: [
 				"com.android.art",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		bootclasspath_fragment {
@@ -220,6 +226,9 @@
 							module: "art-bootclasspath-fragment",
 					},
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 `,
 	)
@@ -361,6 +370,9 @@
 				apex_available: [
 					"com.android.art",
 				],
+				hidden_api: {
+					split_packages: ["*"],
+				},
 			}
 		`, contentsInsert(contents))
 
@@ -853,6 +865,9 @@
 			apex_available: [
 				"myapex",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 	`)
 
@@ -959,6 +974,9 @@
 			apex_available: [
 				"com.android.art",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		apex {
@@ -1010,6 +1028,9 @@
 					module: "art-bootclasspath-fragment",
 				},
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 	`)
 
@@ -1123,6 +1144,9 @@
 			apex_available: [
 				"com.android.art",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		apex {
@@ -1175,6 +1199,9 @@
 					module: "art-bootclasspath-fragment",
 				},
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 	`)
 
@@ -1282,6 +1309,9 @@
 			apex_available: [
 				"com.android.art",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		apex {
@@ -1334,6 +1364,9 @@
 					module: "art-bootclasspath-fragment",
 				},
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 	`)
 
diff --git a/apex/classpath_element_test.go b/apex/classpath_element_test.go
index 60f18bd..9142eed 100644
--- a/apex/classpath_element_test.go
+++ b/apex/classpath_element_test.go
@@ -88,6 +88,9 @@
 				"baz",
 				"quuz",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		java_library {
@@ -134,6 +137,9 @@
 			contents: [
 				"bar",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		java_library {
diff --git a/apex/platform_bootclasspath_test.go b/apex/platform_bootclasspath_test.go
index 06c39ee..4b48da8 100644
--- a/apex/platform_bootclasspath_test.go
+++ b/apex/platform_bootclasspath_test.go
@@ -125,6 +125,7 @@
 					unsupported_packages: [
 							"bar-unsupported-packages.txt",
 					],
+					split_packages: ["*"],
 				},
 			}
 
@@ -274,6 +275,9 @@
 				"baz",
 				"quuz",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		java_library {
@@ -317,6 +321,9 @@
 			name: "my-bootclasspath-fragment",
 			contents: ["bar"],
 			apex_available: ["myapex"],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		apex_key {
@@ -482,6 +489,9 @@
 			contents: [
 				"foo", "bar",
 			],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		prebuilt_bootclasspath_fragment {
@@ -599,6 +609,9 @@
 				generate_classpaths_proto: false,
 				contents: ["foo"],
 				apex_available: ["myapex"],
+				hidden_api: {
+					split_packages: ["*"],
+				},
 			}
 
 			java_library {
@@ -656,6 +669,9 @@
 				contents: [
 					"foo",
 				],
+				hidden_api: {
+					split_packages: ["*"],
+				},
 			}
 
 			platform_bootclasspath {
@@ -696,6 +712,9 @@
 			bootclasspath_fragment {
 				name: "not-in-apex-fragment",
 				contents: ["foo"],
+				hidden_api: {
+					split_packages: ["*"],
+				},
 			}
 
 			platform_bootclasspath {
@@ -746,6 +765,9 @@
 				name: "apex-fragment",
 				contents: ["foo", "bar"],
 				apex_available:[ "myapex" ],
+				hidden_api: {
+					split_packages: ["*"],
+				},
 			}
 
 			platform_bootclasspath {
diff --git a/java/bootclasspath_fragment.go b/java/bootclasspath_fragment.go
index b28d70c..0591012 100644
--- a/java/bootclasspath_fragment.go
+++ b/java/bootclasspath_fragment.go
@@ -858,11 +858,18 @@
 	packagePrefixes := b.sourceOnlyProperties.Hidden_api.Package_prefixes
 	singlePackages := b.sourceOnlyProperties.Hidden_api.Single_packages
 	if splitPackages != nil || packagePrefixes != nil || singlePackages != nil {
-		if splitPackages == nil {
-			splitPackages = []string{"*"}
-		}
 		output.SignaturePatternsPath = buildRuleSignaturePatternsFile(
 			ctx, output.AllFlagsPath, splitPackages, packagePrefixes, singlePackages)
+	} else if !b.isTestFragment() {
+		ctx.ModuleErrorf(`Must specify at least one of the split_packages, package_prefixes and single_packages properties
+  If this is a new bootclasspath_fragment or you are unsure what to do add the
+  the following to the bootclasspath_fragment:
+      hidden_api: {split_packages: ["*"]},
+  and then run the following:
+      m analyze_bcpf && analyze_bcpf --bcpf %q
+  it will analyze the bootclasspath_fragment and provide hints as to what you
+  should specify here. If you are happy with its suggestions then you can add
+  the --fix option and it will fix them for you.`, b.BaseModuleName())
 	}
 
 	return output
diff --git a/java/bootclasspath_fragment_test.go b/java/bootclasspath_fragment_test.go
index 8ffe99a..83beb6d 100644
--- a/java/bootclasspath_fragment_test.go
+++ b/java/bootclasspath_fragment_test.go
@@ -121,6 +121,9 @@
 					],
 				},
 			},
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		java_library {
@@ -201,6 +204,9 @@
 			core_platform_api: {
 				stub_libs: ["mycoreplatform.stubs"],
 			},
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		java_library {
diff --git a/sdk/bootclasspath_fragment_sdk_test.go b/sdk/bootclasspath_fragment_sdk_test.go
index a60039a..93ad172 100644
--- a/sdk/bootclasspath_fragment_sdk_test.go
+++ b/sdk/bootclasspath_fragment_sdk_test.go
@@ -101,6 +101,9 @@
 				image_name: "art",
 				contents: ["mybootlib"],
 				apex_available: ["com.android.art"],
+				hidden_api: {
+					split_packages: ["*"],
+				},
 			}
 
 			apex_key {
@@ -235,6 +238,9 @@
 					// This should be automatically added to the sdk_snapshot as a java_sdk_libs module.
 					stub_libs: ["mycoreplatform"],
 				},
+				hidden_api: {
+					split_packages: ["*"],
+				},
 			}
 
 			java_library {
@@ -453,6 +459,9 @@
 				contents: [
 					"myotherlib",
 				],
+				hidden_api: {
+					split_packages: ["*"],
+				},
 			}
 
 			java_library {
@@ -482,6 +491,9 @@
 						module: "myotherbootclasspathfragment"
 					},
 				],
+				hidden_api: {
+					split_packages: ["*"],
+				},
 			}
 
 			java_sdk_library {
@@ -561,6 +573,9 @@
 			image_name: "art",
 			contents: ["mybootlib"],
 			apex_available: ["myapex"],
+			hidden_api: {
+				split_packages: ["*"],
+			},
 		}
 
 		java_library {
@@ -668,6 +683,7 @@
 					unsupported_packages: [
 							"my-unsupported-packages.txt",
 					],
+					split_packages: ["*"],
 				},
 			}
 
diff --git a/sdk/sdk_test.go b/sdk/sdk_test.go
index e230d5c..1ec12c3 100644
--- a/sdk/sdk_test.go
+++ b/sdk/sdk_test.go
@@ -473,6 +473,9 @@
 				name: "mybootclasspathfragment",
 				apex_available: ["myapex"],
 				contents: ["mysdklibrary"],
+				hidden_api: {
+					split_packages: ["*"],
+				},
 			}
 
 			java_sdk_library {