Hebrews scholarship regularly includes claims that the author used the word οὐρανός in either two or three distinct senses. Most basically, it is argued that the word can refer to created parts of the cosmos or to the uncreated place where God dwells, and that authors who use the word have one of these two distinct referents in mind. This is particularly important in Hebrews 12.25–9, where the οὐρανός is shaken. It is often argued that this must be the created οὐρανός in distinction to the divine or eternal οὐρανός. This article critiques this common understanding of οὐρανός and its application to Hebrews 12.25–9. First, it surveys some early Jewish and Christian texts that discuss humans ascending into heaven, illustrating that these texts do not indicate any ontological divisions between various entities named ‘heaven’. Second, it briefly examines the ten occurrences of οὐρανός in Hebrews against this background, and it becomes clear that the author of Hebrews was more interested in contrasting heaven and earth (and perhaps the highest from the lower heavens) than in separating ‘heaven’ into distinct realms based on ontology. Third, the article outlines the significance of this conclusion for understanding what Hebrews 12.25–9 says about the shaking of heaven and earth. The author of Hebrews does not mean that some uncreated οὐρανός will ‘remain’ while the created heavens and earth are shaken. Instead, all of the heavenly and earthly space will be shaken.